Multiple polymeric additive systems: compositions, processes, and products thereof

ABSTRACT

The present invention provides multiple polymeric additive systems and processes for preparing multiple polymeric additive systems which contain a liquid component and a solid component, wherein the solid component contains two or more polymeric additive particles having different compositions. The present invention also provides polymeric compositions and processes for preparing polymeric compositions that include a polymeric component and a multiple polymeric additive system which contains a liquid component and a solid component, wherein the solid component contains two or more polymeric additive particles having different compositions. The disclosed compositions and processes are useful in the preparation of polymeric materials and articles produced therefrom.

BACKGROUND OF THE INVENTION

[0001] This invention relates to compositions which are useful asmultiple polymeric additive systems. This invention also relates toprocesses for making multiple polymeric additive systems. This inventionfurther relates to polymeric compositions that include a polymericcomponent and a multiple polymeric additive system. This invention evenfurther relates to processes for preparing polymeric compositions thatinclude a polymeric component and a multiple polymeric additive system.

[0002] Numerous molded articles and films are manufactured from one ormore of a variety of polymeric resins. Often times, these resins, bythemselves, do not possess all of the properties required by the end usefor which they are made. To overcome their shortcomings, these resinsare generally blended with other components which exhibit the desiredproperties. Such components are typically known in the industry as“polymeric additives”. There are many varieties of polymeric additivesknown, and each of these are available in a variety of physical forms(e.g., gas, liquid, solid, and combinations thereof) and chemical forms(e.g., organic, inorganic, metallic, non-metallic, polymeric,non-metallic, and combinations thereof).

[0003] Although polymeric additives can be made by a number of differentways, many are made by emulsion polymerization. Thereafter, the emulsionis dried to form a powder. The powder is then blended with the polymericresin system whose properties need to be enhanced.

[0004] Accordingly, since many polymeric additives are blended with thepolymeric resin when the additive is in a powder form, one significantlimitation upon the development and/or selection of new polymericadditives is their ability to form a stable powder. The term “stable” asit pertains to powders means, among other things, the ability of theparticles making up the powder to remain in a flowable form duringnormal storage, handling and processing procedures. One reason for theexistence of this problem is that many polymeric additives arerelatively soft. Accordingly, they often have the tendency to sticktogether; thus, reducing the additive's stability. This phenomenon isoften seen in polymeric additives designed to enhance the impactmodification of the polymeric resin system since, in order to impartthis property, the additive generally needs to be soft and/or rubbery.

[0005] One means of addressing this problem has been to usemulti-layered multiple polymeric additive systems. Such systems aretypically known in the industry as a “core/shell” system. In mostcore/shell systems, the inner stage (i.e., the core) is relatively softand/or rubbery; and the outer-stage (i.e., the shell) is relativelyhard. The hardness of the outer shell keeps the particles from stickingtogether.

[0006] Polymer additives have also been developed for the purpose ofmodifying the processing characteristics of plastics resins. These“processing aids” are generally high in molecular weight, typicallyabove 1 million g/mol, and are compatible with the plastic resin.However, dried processing aid powders are typically dusty and therebydifficult to handle.

[0007] It is therefore desirable to combine compositionally differentpolymeric additive particles to provide two or more functions, such as acombination of impact modifiers and processing aids. One way ofcombining an impact modifier polymeric additive particle with aprocessing aid polymeric additive particle is disclosed in U.S. Pat. No.5,276,092. This Patent discloses core/shell impact modifier having anemulsion solids fraction less than 40% and processing aid additiveswhich are prepared separately at small particle sizes by emulsionpolymerization, co-agglomerated, further encapsulated by a final shell,and preferably isolated to a dry powder by spray-drying or coagulation.

[0008] While the use of co-agglomeration and an encapsulating shellpolymer has been used to provide emulsion blends of two compositionallydifferent polymeric additive particles, such aqueous systems are stillfraught with other problems. For example, these aqueous systems arelimited to low (less than 40%) solids weight fractions having more than60% by weight water. Ordinarily, this water needs to be removed so thatthe process of preparing blends of resins and such aqueous dispersionsis inefficient in requiring the removal of such large quantities ofwater.

[0009] Often times, the isolation of polymeric additive particles asdried powders will vary depending on the physically and chemicalcomposition of the particle. Accordingly, co-isolating two or moredifferent additive particles is at best complicated. For example, theproblems seen during the co-isolation of impact modifiers and processingaids typically result in dispersion problems of the additives into theresins because one of the additive particles may have a greater affinityfor the liquid phase, or be a lot more or a lot less stable as a colloidin the liquid phase, and therefore the distribution of polymericadditive particles in such a co-isolated powder will vary. For example,it is typical that during co-isolation, one population of particles willisolate separately from the other population. Accordingly, avoiding theneed to co-isolate multiple polymeric additive particles is desirable inavoiding these problems.

[0010] Notwithstanding the aforementioned problems associated withpowdery plastic additive systems, they are still the additive system ofchoice. However, the industry continues to look for alternatives to suchsystems. One of the alternatives that has been suggested is disclosed inU.S. Pat. No. 3,864,432. The multiple polymeric additive systemdisclosed in this Patent is not in a powder form, yet it is used toimprove the impact strength of PVC resins. U.S. Pat. No. 5,276,092 alsodiscloses that the emulsion product of encapsulated, co-agglomeratedcore/shell impact modifier and processing aid additives are preferablyisolated to a dry powder by spray-drying or coagulation, but may be usedstill in an emulsion form.

[0011] While such a system can be used, there are many advantagesassociated with using higher solids systems that provide either improvedproperty enhancements and/or two or more property enhancements. Forexample, some of the advantages of using higher solids systems thatprovide improved property enhancements include combining polymericadditives wherein at least one of the additives is not readilyisolatable as a powder. Specifically, in the area of impactmodification, it is desirable to add rubbery materials to brittleplastics in order to increase their ability to absorb impact stress.Although typical impact modifiers are in the form of core/shell polymerparticle powders, it is desirable to further incorporate other rubberymaterials which often are not readily available in a powder form. Oneexample of a rubbery material which is not readily isolatable as apowder, includes solution-polymerized rubbery polymers such assolution-made styrene/diene block copolymers. Other rubbery materialswhich are desirable for incorporation into multiple polymeric additivesystems include rubbery emulsion polymer particles which are not readilyisolatable in a powdery form. Yet other rubbery materials which aredesirably incorporated into impact modifying polymeric additivecompositions include liquid polymers which are not readily isolatable asa powder. Examples of such liquid polymer include a polymeric oil, suchas: low molecular weight polybutene, polysiloxane, certain mineral oils,liquid polysulfide, and the like.

[0012] For example, some of the advantages of using higher solidssystems that two or more property enhancements include combiningpolymeric additives wherein at least one of the polymeric additives isan impact modifier and the other polymeric additive is a processing aid.

[0013] Many plastics additives which are not necessarily polymeric arealso commonly used in the plastics industry to modify the processabilityand/or properties of polymeric resins. Examples of these other additivesinclude: waxes; pigments; opacifiers; fillers; exfoliated clays; toners;antistatic agents; metals; flame retardants; thermal stabilizers;antioxidants; cellulosic materials; internal lubricants; externallubricants; oils; rheology modifiers; powder flow aids; dispersing aids;UV stabilizers; plasticizers; fillers; optical modifiers; surfaceroughness modifiers; surface chemistry modifiers; adhesion modifiers;surface hardeners; compatibilizers; diffusion barrier modifiers;stiffeners; flexibilizers; mold release agents; processing modifiers;blowing agents; thermal insulators; thermal conductors; electronicinsulators; electronic conductors; biodegradation agents; antistaticagents; internal release agents; coupling agents; flame retardants;smoke-suppressers; colorants, and the like, and/or combinations thereof.

[0014] As seen by the examples set out above, many plastics additivescome in a variety of physical forms such as volatile liquids, pastywaxes, dusty powders, hard solids, and the like. Accordingly, they areoften handled separately when formulating a polymeric compositioncontaining these additives. This creates obvious problems, especiallywhen some of the additives come in a liquid form, while others that areneeded come in a powder form. Other inherent problems with theconventional ways of enhancing the properties of a polymeric compositionthrough the use of a polymeric additives include: handling dusty powderswhich requires special handling to avoid breathing of powders, explosionhazards arising from static electricity build-up, contamination, generaldifficulty in handling and containing dusty materials; handling pelletsrequires separate operational processes than that of powders makingprocesses more complex and/or expensive requiring further equipment;minor ingredients (such as low solid fraction) are difficult to handleand evenly disperse in polymeric resins using conventional processes.

[0015] Notwithstanding the problems associated with conventionalmultiple polymeric additive systems, they will almost always benecessary due to the inherent deficiencies of polymeric compositions.However, the industry is continually searching for improved multiplepolymeric additive systems which resolve at least some of theaforementioned problems.

SUMMARY OF THE INVENTION

[0016] Accordingly, one object of the present invention is to providemultiple polymeric additive systems which contain a liquid component anda solids component, wherein the solids component contains two or morepopulations of compositionally different polymer particles, and whereinthe solids component is present in an amount of more than 40 weightpercent, said weight percentage being based on the total weight of themultiple polymeric additive system.

[0017] Another object of the present invention is to provide processesfor making multiple polymeric additive systems which contain a liquidcomponent and a solids component, wherein the solids component containstwo or more populations of compositionally different polymer particles,and wherein the solids component is present in an amount of more than 40weight percent, said weight percentage being based on the total weightof the multiple polymeric additive system.

[0018] Yet another object of the present invention is to providepolymeric compositions that include a polymeric component and a multiplepolymeric additive system which contains a liquid component and a solidscomponent, wherein the solids component contains two or more populationsof compositionally different polymer particles, and wherein the solidscomponent is present in an amount of more than 40 weight percent, saidweight percentage being based on the total weight of the multiplepolymeric additive system.

[0019] Still another object of the present invention is to provideprocesses for preparing polymeric compositions that include a polymericcomponent and a multiple polymeric additive system which contains aliquid component and a solids component, wherein the solids componentcontains two or more populations of compositionally different polymerparticles, and wherein the solids component is present in an amount ofmore than 40 weight percent, said weight percentage being based on thetotal weight of the multiple polymeric additive system.

[0020] These and other objects, as will become apparent from thefollowing disclosure, are achieved by the various embodiments of thepresent invention set out below.

[0021] In one embodiment of the present invention, there is provided anovel multiple polymeric additive system which includes a liquidcomponent and a solids component. In this embodiment, the solidscomponent includes at least two different populations of polymericadditive particles. These particles differ with regard to at least theirchemical composition, and can further differ with regard to at least oneof the following: the property which they will impart to a polymericcomposition into which they can be added, their size, their physicalstate, and/or their shape. Also in this novel multiple polymericadditive system, the solids component is present in an amount which isgreater than 40 weight percent, wherein the weight percentage is basedon the total weight of the multiple polymeric additive system.

[0022] In another embodiment of the present invention, there is provideda novel polymeric composition which includes a polymeric component and apolymeric additive component. In this embodiment, the novel polymericcomposition is prepared by a process which includes the step of forminga blend of at least the polymeric component and a multiple polymericadditive system. In this embodiment, the multiple polymeric additivesystem includes a liquid component, and a solids component. The additivesystem's solids component, in turn, includes at least two differentpopulations of polymeric additive particles. These polymeric additiveparticles differ with regard to at least their chemical composition, andcan further differ with regard to at least one of the following: theproperty which they will impart to a polymeric composition into whichthey can be added, their size, their physical state, and/or their shape.

[0023] In yet another embodiment of the present invention, there isprovided a novel process for making a multiple polymeric additive systemwhich has a liquid component and a solids component, the solidscomponent including polymeric additive particles. The processencompassed by this embodiment includes at least the following steps.First, an aqueous emulsion polymerization reaction mixture is providedwhich includes a first and second population the polymeric additiveparticles. Then, a first group of one or more ethylenically unsaturatedmonomers is polymerized in the aqueous emulsion so that at least one ofsaid populations of polymeric additive particles increases in meanparticle diameter. In this embodiment, after a portion of the firstgroup of one or more ethylenically unsaturated monomers is polymerized,the chemical compositions of the first and second populations ofpolymeric additive particles are different. Also, the solids componentis present in an amount which is greater than 40 weight percent, whereinthe weight percentage is based on the total weight of the multiplepolymeric additive system.

[0024] In still another embodiment of the present invention, there isprovided a novel process for making a multiple polymeric additive systemhaving a liquid component and a solids component. The processencompassed by this embodiment includes at least the following steps.First, an aqueous emulsion polymerization reaction mixture is providedwhich includes a first population and second population of polymerparticles. Then, a first group of one or more ethylenically unsaturatedmonomers is polymerized in the aqueous emulsion such that at least athird population of polymeric additive particles is formed. In thisembodiment of the present invention, after a portion of the first groupof one or more ethylenically unsaturated monomers is polymerized, thechemical compositions of at least two of the populations of polymericadditive particles are different.

[0025] In a further embodiment of the present invention, there isprovided a novel process for making a polymeric composition, wherein thepolymeric composition includes a polymeric component and multiplepolymeric additive system, and wherein the multiple polymeric additivesystem includes a liquid component and a solids component having atleast two different populations of particles. In this embodiment, thechemical compositions of the first and second populations of polymericadditive particles are different. Also, the solids component is presentin an amount which is greater than 40 weight percent, wherein the weightpercentage is based on the total weight of the multiple polymericadditive system. In this embodiment, the polymeric component is firstblended with the multiple polymeric additive system to form a mixture.Then, in a subsequent step, at least a portion of the multiple polymericadditive system's liquid component is at least partially removed fromthe mixture.

[0026] While the invention disclosed herein is susceptible to variousmodifications and alternative forms, specific embodiments thereof areherein described in detail. It should, however, be understood that thedescription herein of specific embodiments is not intended to limit theinvention to the particular forms disclosed. On the contrary, as will beapparent to those skilled in the art after reading this specification,the invention covers all modifications, equivalents and alternativesfalling within the spirit and scope of the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

[0027] The term “polymer” used herein denotes a molecule having two ormore units derived from the same monomer component, so that “polymer”incorporates molecules derived from different monomer components to forform copolymers, terpolymers, multi-component polymers,graft-co-polymers, block-co-polymers, and the like.

[0028] The term “rubbery” used herein denotes the thermodynamic state ofa polymer above its glass transition temperature.

[0029] The term “units derived from” used herein refers to polymermolecules that are synthesized according to known polymerizationtechniques wherein a polymer contains “units derived from” itsconstituent monomers.

[0030] The term “molecular weight” used herein refers to the weightaverage molecular weight of polymer molecules as determined by the gelpermeation chromatography method.

[0031] The term “graftlinker” used herein refers to multi-functionalmonomers capable of forming multiple covalent bonds between polymermolecules of one type with polymer molecules of another type.

[0032] The term “crosslinker” used herein refers to multi-functionalmonomers capable of forming two or more covalent bonds between polymermolecules of the same type.

[0033] The term “alkyl (meth)acrylate” used herein refers to both alkylacrylate and alkyl methacrylate monomer compounds.

[0034] The term “stage” used herein is intended to encompass itsbroadest possible meaning, including the meaning conveyed in prior artsuch as in U.S. Pat. No. 3,793,402; U.S. Pat. No. 3,971,835; U.S. Pat.No. 5,534,594; and U.S. Pat. No. 5,599,854; which offer various meansfor achieving “staged” polymers.

[0035] The term “parts” used herein is intended to mean “parts byweight”. Unless otherwise stated, “total parts by weight” do notnecessarily add to 100.

[0036] The term “weight percent” used herein is intended to mean “partsper hundred by weight” wherein the total parts add to 100.

[0037] The term “multiple polymeric” used herein refers to a compositionhaving two or more polymeric components.

[0038] All ranges defined herein are inclusive and combinable.

[0039] As will be set out below, the embodiments of this inventionpertain to various aspects of a plastic additive system that includes aliquid and solids component, methods of making such additive systems,plastic compositions that include such systems, and/or methods of makingsuch plastic compositions.

[0040] Among other things, this invention resolves at least some of theproblems associated with the use of powdery plastic additive systemswhile improving a plastic resin's properties and or processing thereof.This invention also resolves at least some of the problems associatedwith the use of powdery plastic additive systems while providing two ormore functional improvements to a plastic resin's properties and orprocessing thereof. This is accomplished by the development of novelplastic additive systems that include a liquid component and a solidscomponent including at least two polymeric additive particlepopulations. Accordingly, when practicing this invention, the multiplepolymeric additive systems' liquid concentration is typically greaterthan 1 weight percent; more typically greater than 10 weight percent;and even more typically, greater than 35 weight percent. These weightpercentages are based on the total weight of the multiple polymericadditive system.

[0041] In one specific embodiment of the present invention, there isprovided a novel multiple polymeric additive system which includes aliquid component and a solids component. In this embodiment, the solidscomponent is present in an amount which is greater than 40 weightpercent, wherein the weight percentage is based on the total weight ofthe multiple polymeric additive system. Also in this novel multiplepolymeric additive system, the solids component includes at least twodifferent populations of polymeric additive particles. Various polymericadditives include impact modifiers, processing aids, lubricatingprocessing aids, powder flow aids, dispersing aids, rheology modifiers,matting agents, gloss improvers, antistatic agents, flame retardants,coupling agents, thermoset resins, pigment dispersant, fillerdispersants, clay dispersants, wetting agents for compatibilizing glassfibers with polymeric resins, and the like.

[0042] Polymeric impact modifiers are typically provided by thefollowing types of compositions: all polymeric rubbery materials such asthose derived from acrylics, methylmethacrylate-butadiene-styrene(“MBS”) type impact modifiers; silicon-containing rubber polymers andcopolymers such as siloxanes, silicones, and the like; polymerscontaining flexible chains for reducing glass transition temperature,such as polyesters; chlorinated polyethylene (“CPE”);ethylene-vinylacetate polymers (“EVA”); acrylonitrile-butadiene-styrene(“ABS”) polymers; carboxy-terminated butadiene-nitrile (“CTBN”)polymers; ethylene-propylene-diene monomer (“EPDM”) polymers;polyolefins; vinylaromatic-diene block copolymers; synthetic rubber,such as butadiene rubber, styrene-butadiene rubber (“SBR”), andisoprene, and the like; polyurethanes; rubbery polyethers such as anethylene glycol and propylene-glycol based polymers, and the like; aswell as blends, grafts, and copolymers thereof.

[0043] Impact modifiers are typically present in polymer resins at aweight percentage in the range of from 0.5 to 50 weight percent, moretypically in the range of from 1 to 30 weight percent, and mosttypically in the range of from 2 to 20 weight. Engineering resinstypically have about 10 to 20 weight percent impact modifiers; polyvinylchloride (“PVC”) typically has about 2 to 15 weigh percent;thermoplastic elastomers typically have 20 to 50 weight percentage ofimpact modifiers.

[0044] Polymeric processing aids are typically provided by the followingtypes of compositions: polyesters, (meth)acrylic ester-containingpolymers, styrenics, SAN, PVA, EVA-type, vinyl halogen polymers such asPVDF, fluorinated polymers such as PTFE, CTFE, PVC-acrylic copolymers,polyethers, polyolefin-polystyrene copolymers, acrylic-modifiedpolyolefins, (meth)acrylic acid-containing polymers, and blends, grafts,and copolymers thereof.

[0045] Processing aids are typically present in polymer resins at aweight ratio of from 0.1 weight percent to 20 weight percent. Moretypically from 0.25 weight percent to 15 weight percent. Most typicallyfrom 0.5 weight percent to 8 weight percent, the weight percentage beingbased on the weight of the polymeric component.

[0046] Polymeric lubricating processing aids as known in the art providea lubricating effect and a melt processing effect when added topolymeric melt components. Typical lubricating processing aids can beprovided by compositions provided for by processing aids wherein alubricating component is added, as known in the art.

[0047] Lubricating processing aids are typically present in polymerresins at a weight ratio of from 0.05 weight percent to 10 weightpercent. More typically from 0.1 weight percent to 7 weight percent.Most typically from 0.2 weight percent to 5 weight percent, the weightpercentage being based on the weight of the polymeric component.

[0048] Polymeric powder flow aids are typically provided by thefollowing types of compositions: silicon-based polymers; fumed silicon;hard organic polymers, such as those having a Tg greater than about 60°C., acrylics, styrenics, polymeric-coated particles such as polystearicacid-coated calcium carbonate, and the like.

[0049] Powder flow aids are typically formulated in polymer resinpowders and polymer dispersions. Powder flow aids are typically presentat a weight ratio of from 0.05 weight percent to 10 weight percent. Moretypically from 0.1 weight percent to 7 weight percent. Most typicallyfrom 0.2 weight percent to 5 weight percent, the weight percentage beingbased on the weight of the polymeric component.

[0050] Compositions of polymeric dispersion aids, which are typicallyknown in the art as “Dunkelspersers”, are disclosed in U.S. Pat. No.4,440,905, the portion of which relates to the composition and use ofpolymeric dispersion aids is incorporated by reference herein.

[0051] Polymeric melt rheology modifiers are typically provided by thefollowing types of compositions: olefin-polar polar graft copolymerssuch as olefin-acrylic graft copolymers, olefin-styrene graftcopolymers, and the like; oxidized polyolefins; EVA; long-chain alkyl(meth)acrylates, and the like as known in the art; as well as grafts,and blends, and copolymers thereof.

[0052] Polymeric melt rheology modifiers are typically present inpolymer resins at a weight ratio of from 0.05 weight percent to 10weight percent. More typically from 0.1 weight percent to 7 weightpercent. Most typically from 0.2 weight percent to 5 weight percent, theweight percentage being based on the weight of the polymeric component.

[0053] In one specific embodiment of the present invention, the multiplepolymeric additive system's solid component contains two or more of thepolymeric additives previously described. The weight ratios of such twoor more polymeric additives in the multiple polymeric additive system isdetermined by combining the weight percentage ranges that each polymericadditive is used in modifying a polymeric resin. Thus, in a specificexample, the weight ratio of impact modifier polymer particles toprocessing aid polymer particles in the solids component of a multiplepolymeric additive system will range from 0.5:20 to 50:0.1. Examples ofother weight ratios of two or more polymeric additive particles can bedetermined by the weight percentages provided above.

[0054] Any suitable means can be used to produce a plastic additivesystem having, among other things, a solid component greater than 40weight percent. One example of such a suitable means is to blend two ormore populations of polymeric additive particles, each population havingan excess of 40 weight percent polymer particles. Another example ofsuch a suitable means is to blend two or more populations of polymericadditive particles, one population having an excess of 40 weight percentpolymer particles and the other population having less than 40 weightpercent polymer particles so that the combination has an excess of 40weight percent polymer particles. Another example of such a suitablemeans is to employ as part of the solid component at least twodifferently-sized populations of particles.

[0055] Although one specific embodiment of the invention requires thatthe particle size of the at least two populations of particles merely bedifferent, it has been observed that higher solids concentrations can beachieved when the particle size of the first population of particles isat least 50% larger than that of the second population of particles. Ininstances where even higher solids concentration are desirable, theparticle size of the first population of particles is at least 100%larger than that of the second; more typically at least 200% larger thanthat of the second population; and even more typically at least 250%larger than that of the second population.

[0056] However, it has also been observed that having the particle sizedifference too great can cause some problems. Accordingly, whenpracticing this embodiment of the invention, the particle size of thefirst population of particles is typically not greater than 10,000%larger than that of the second population of particles; more typicallynot greater than 1,000% larger than that of the second population; andeven more typically not greater than 300% larger than that of the secondpopulation. These size differences are particularly preferred forpreparing polymeric additive particles which are useful as impactmodifiers. For the purposes of creating a multiple polymeric additivesystem that flows well, in one preferred embodiment the particle sizedifference is in the range of from 700% to 1,000%.

[0057] When the multiple polymeric additive system is essentially thereaction product of an emulsion polymerization reaction containing twoor more populations of polymer particles, the limit on solids weightfraction is theoretically limited. When looking at a combination of twopolymer populations which vary in particle size, there are three mainvariables: weight percent of large population “mode”, particle size ofthe large mode and particle size of small mode. Diameter Ratio (DR) isequal to the diameter of the large mode (Dlarge) divided by the diameterof the smaller mode (Dsmall). From a theoretical standpoint the optimumvalue of DR for maximizing packing density ranges from about 7 to about10.

[0058] In comparison to randomly packed ideal single mode spheres whichhas a packing factor of 0.639, a combination of large mode and smallmode spheres having a DR of 10 provides a packing factor of 0.835, whilea DR of infinity will give 0.870. Hence, any further increase in the DRabove about 10 gives a marginal increase in packing density.

[0059] To achieve the maximum packing factor for a combination of largemode and small mode polymer particles, the weight percent of the largepolymer particles should be about 73.5%. While this value is for anideal system for merely maximizing the packing effects, the weightpercent of the large polymer particles may vary depending on propertiessought by the polymer particles. For example, impact modifiers tend toprovide better impact strength to polymeric resins as the particle sizedecreases, thus the weight percent of large impact modifier polymerparticles may be best less than 73.5%.

[0060] In addition, a combination of three or more populations ofpolymer particles “multi-populations” which varying in particle size canprovide further increases in the packing fraction beyond the theoreticalvalue of 87% for two populations of polymer particles. Further increasesare expected in “multi-populations” of polymer particles as theinterstitial spaces in the two-population system can be further filledby even smaller particles.

[0061] From a practical standpoint involving emulsion-polymerizedpolymeric additive particles, the optimum particle size distribution istypically determined by the latex properties desired. However, theseproperties vary depending on the application. While having a largeDiameter Ratio might be ideal for maximizing the packing fraction, alarge DR does not necessarily provide ideal application properties.

[0062] In the embodiment of this invention wherein the multiplepolymeric additive system's solid component has at least twodifferently-sized populations of particles, the larger-sized populationtypically has a mean particle diameter in the range from about 10 nm toabout 50,000 nm. More typically, the larger-sized population has a meanparticle diameter in the range from about 50 nm to about 1,500 nm; evenmore preferably from about 100 nm to about 1,000 nm; and even morepreferably from about 300 nm to about 600 nm.

[0063] For providing additives useful as impact modifiers, it isdesirable that the mean particle diameter of the smaller population hasa particle size of about 100 to 150 nm. Maximizing the weight fractionof the smaller population is desirable for improving impact strength.Often, the mean particle diameter of impact modifier particles of thesmall mode is most desirably in the range of from about 100 to 120 nm,especially where the particle solids concentration about 50%. At higherweight percent solids of about 65%, it is desirable that the meanparticle diameter of the smaller population is in the range of about 225to 275 nm. Accordingly, the larger population at about 50% solids ismost desirably in the range of about 300 nm to 350 nm. At concentrationsof about 65%, the mean part diameter of the larger pop is mostpreferably in the range of from 500 to 600 nm.

[0064] Impact modifier polymeric additive particles typically havegreater than 50% of a rubbery component, more typically greater than 70%of a rubbery component, and most typically greater than 80% of a rubberycomponent. For maximizing impact efficiency it is desirable that therubbery component approaches 100 weight percentage of the polymerparticle.

[0065] In one embodiment of the present invention, the multiplepolymeric additive system contains polymeric additive particles whichmay be selected from the following group: impact modifiers;plasticizers; processing aids; reinforcers; heat distortion improvers;lubricating processing aids; optical modifiers; hollow spheres; surfacemodifiers; and combinations thereof Other polymeric additive particlesinclude those which are useful for modifying surface properties.Polymeric additive particles may also be used to: improve melt flow(index) or melt strength; improve flame retardancy; improve thermalstability properties; and to reduce plate-out in extruders. Moreover,such particles may also be used to reduce “sagging” that often takesplace during or after thermoforming of polymeric materials.

[0066] In another embodiment, the solid component of the multiplepolymeric additive system contains polymeric additive particles whichare useful as processing aids. Typically, processing aids have polymercompositions exhibiting a glass transition (“Tg”) higher than about 25°C. Typically, processing aids have polymer compositions with molecularweights (“MW”) greater than about 1 million g/mol. More typically,processing aids have molecular weights greater than about 3 milliong/mol. In certain applications, such as preparing PVC foam, processingaids may have molecular weights greater than about 6 million.

[0067] As used herein, the term “compositionally” refers to theparticles' chemical composition. The particles can have any suitablechemical composition as long as the compositions of the first and secondpopulations are essentially different. Typically, the particles have achemical composition that, in some way, enhances at least one physicalproperty of the polymeric composition into which it will be added. Theparticle's chemical composition can, however, be that of an inertfiller.

[0068] Examples of a particle's chemical composition may include: waxes;pigments; opacifiers; exfoliated clays; toners; antistatic agents;metals; flame retardants; thermal stabilizers; co-stabilizers;antioxidants; cellulosic materials; impact modifiers; processing aids;lubricating processing aids; internal lubricants; external lubricants;oils; rheology modifiers; powder flow aids; melt-flow aids; dispersingaids; UV stabilizers; plasticizers; fillers; optical modifiers; surfaceroughness modifiers; surface chemistry modifiers; adhesion modifiers;surface hardeners; compatibilizers; diffusion barrier modifiers;stiffeners; flexibilizers; mold release agents; processing modifiers;blowing agents; thermal insulators; thermal conductors; electronicinsulators; electronic conductors; biodegradation agents; antistaticagents; internal release agents; coupling agents; flame retardants;smoke-suppressers; anti-drip agents; colorants; and the like.

[0069] The particles' preferred chemical composition will depend, inpart, on the desired end use of the plastic additive system and/or thepolymeric composition into which they are to be added. Those skilled inthe art would be able to readily determine the particles' chemicalcomposition which best suits their needs after reading thisspecification.

[0070] Also as used herein, the term “dimensionally” refers to theparticles' size and/or shape. With regard to their shape, the particlesmaking-up the additive systems' solid component are typicallyspherically-shaped. However, they can have any suitable shape. Variousshapes of polymer particles can be prepared by processes known in theart of polymer particle technology. Examples of such suitable shapes ofparticles include: rubbery core/hard shell inhomogeneous particles, hardshell/rubbery core particles, particles having more complex (e.g.three-stage, hard/soft/hard; four-stage soft/hard/soft/hard, etc.)morphologies; ellipsoidal particles having an aspect ratio greater than1:1; raspberry-shaped particles; multi-lobe-shaped particles;dumbbell-shaped particles; agglomerated particles; bilobal particles;hollow sphere particles; and the like.

[0071] With regard to their size, this typically refers to their meanparticle size. Accordingly, in the case where the particles arespherically-shaped, this refers to their mean particle diameter.

[0072] The particles' preferred dimension will depend, in part, on thedesired end use of the plastic additive system and/or the polymericcomposition into which they are to be added. Those skilled in the artwould be able to readily determine the particles' dimension which bestsuits their needs after reading this specification.

[0073] It is within the purview of this invention for the first andsecond populations of polymer particles to be at least compositionallydifferent from one another. However, it is within the purview of thisinvention that the first and second populations of polymer particlesare, in all other aspects, identical to each other, or completelydifferent to each other, or anything in between. The particles'preferred dimensional and chemical configuration will depend, in part,on the desired end use of the plastic additive system and/or thepolymeric composition into which they are to be added. Those skilled inthe art would be able to readily determine the configuration which bestsuits their needs after reading this specification.

[0074] As stated above, the embodiments of this invention resolve atleast some of the problems associated with the use of powdery plasticadditive systems by the development of novel plastic additive systemsthat include a liquid component. In the multiple polymeric additivesystem of the present invention the liquid component can include anysuitable liquids.

[0075] Typically, the additive's liquid component contains at least somewater. The liquid component of the multiple polymeric additive systemsof the present invention may contain water. Although water may be absentfrom the liquid component, typically the liquid component will containat least 10 weight percent water, more typically at least 50 weightpercent water, and most typically at least 80 weight percent water. Evenmore typical, the liquid is essentially 100% weight percent water, saidweight percentage being based on the total weight of the multiplepolymeric additive system's liquid component. However, it is within thepurview of this invention for the additive's liquid component to containessentially no water.

[0076] The specific selection of liquids that make-up the additive'sliquid component depends, in part, on the additive's desired end useand/or preparation. Examples of liquids that can be used to make up atleast part of the additives' liquid component include at least one ofthe following: water, organic solvents, alcohols, esters, plasticizers,emulsion stabilizers, defoamers, leveling agents, biocides,mildewicides, fungicides, UV stabilizers, lubricants, oils, dyes,rheology modifiers, thermal stabilizers, co-stabilizers, antioxidants,mold release agents, oligomers, monomers, crosslinkers, graftlinkers,curing agents, reactants, and the like. Moreover, the additives' liquidcomponent can also include liquid polymeric additives designed toenhance at least some of the properties of the polymeric compositioninto which they will be added. Examples of such liquid polymericadditives include: oligomers, low molecular weight polymers, rubbers,uncured coating components, uncured polymeric components, e.g.,thermoset components, and the like. Most typically, where the liquidcomponent contains essentially no water, the liquid component mayinclude oils, oligomers, stabilizers, monomers, lubricants, combinationsthereof, and the like.

[0077] It is within the purview of this invention for the additive'sliquid component to be made up of only one liquid, or a number ofdifferent liquids. The preferred composition of the additive's liquidcomponent will depend, in part, on the desired end use of the plasticadditive system and/or the polymeric composition into which they are tobe added. Those skilled in the art would be able to readily determinethe composition of the additive's liquid component which best suitstheir needs after reading this specification.

[0078] Other additives available in a liquid form include monomers,oligomers, and liquid rubbers. Particularly useful combinations ofliquids include but are not limited to: stabilizers plus lubricants;water, emulsifiers and antioxidants; water, emulsifiers, oils or othernon-water soluble ingredients, e.g. oil in water emulsions ordispersions). These combinations are useful for the purposes of uniformincorporation and dispersion of active stabilizing ingredients ornonwater soluble additives. Various other useful combinations of liquidadditives can be readily prepared by those skilled in the art.

[0079] In one embodiment of the multiple polymeric additive system ofthe present invention the liquid component may contain essentially nowater. In this case, the liquid component may be any of the above namedliquids, e.g. especially oils, oligomers, stabilizers, monomers,lubricant. In this case the absence of water can be provided by dryingthe polymer particles according to the emulsion polymerization processesdescribed earlier. Suitable drying steps include, for example, spraydrying, coagulation, freeze drying). Multiple polymeric additive systemscontaining essentially no water are then provided by mixing the drypolymer particles with a liquid.

[0080] In one embodiment for preparing a multiple polymeric additivesystem, the first population of polymer additive particles of the solidcomponent are compositionally different from the second population ofpolymeric additive particles. Compositionally different populations ofpolymer particles can be provided by the following procedures:post-blending of two compositionally distinct lattices or solutions,in-situ formation and polymerization of a second particle population inthe presence of a previously polymerized particle population. In anotherexample, two seeds having similar swelling characteristics and differentpolymerization characteristic can also be provided for preparingcompositionally different polymeric additive particles.

[0081] For example, when the reactivity ratios of two or more monomersare quite different, then copolymerizing a mixture of these two or moremonomers would essentially result in separate populations of polymerparticles, each population being derived substantially from eachmonomer. It is believed that this mechanism is driven by monomer/seedthermodynamics wherein the monomers partition among the seed particles.

[0082] Two different populations of particles which are compositionallydifferent can also be prepared wherein the kinetics of polymerizationvary among the two monomers. One specific example is where butadiene(“BD”) monomer, which polymerizes via free radical polymerization muchmore slowly than methyl methacrylate monomer (“MMA”). In this example,providing a BD/MMA mixture to would result in the formation ofMMA-derived polymer seed particles first; subsequently adding excesssoap results in the formation of BD-derived polymer seed particles.Overall, balancing thermodynamics and the kinetics will generallyprovide a range of different polymer particle populations using themethods described herein.

[0083] In one specific embodiment of the present invention, there isprovided a novel multiple polymeric additive system which includes aliquid component and a solids component, wherein the solids componentincludes at least two populations of compositionally different polymericadditive particles, and wherein the solids component is present in anamount greater than 40 weight percent. Although this embodiment of theinvention requires that the additive system's solids component be merelygreater than 40 weight percent, it has been observed that even highersolids concentrations have certain advantages associated therewith.Accordingly, when practicing this embodiment of the invention, theadditive system's solids component is typically greater than 45 weightpercent; more typically greater than 50 weight percent; and even moretypically, greater than 55 weight percent.

[0084] Any suitable means can be used to produce a plastic additivesystem having, among other things, a solids component greater than 40weight percent. One example of such a suitable means is to employ aspart of the solids component at least two differently-sized populationsof particles.

[0085] The multiple polymeric additive systems of the present inventioncan be in any suitable form, including powders, pellets, and tabletscontaining the liquid component. Typically, the multiple polymericadditive system is in one of the following forms: an emulsion, a latex,a suspension, a slurry, a dispersion, a wet-cake, a paste, and the like.

[0086] The preferred form of the plastic additive systems encompassed bythis invention will depend, in part, on the desired end use of theplastic additive system and/or the polymeric composition into which theyare to be added. Those skilled in the art would be able to readilydetermine the form which best suits their needs after reading thisspecification.

[0087] In the embodiment wherein the plastic additive system is in anemulsion form, the additive's liquid component is generally present inan amount of at least about 1 weight percent. Typically, when in thisform, the additive's liquid component is present in an amount of atleast about 5 weight percent; more typically of at least about 10 weightpercent; and even more typically in an amount of at least about 20weight percent. On the other hand, when in the emulsion form, theadditive's liquid component is generally present in an amount of notgreater than about 60 weight percent. Typically, when in this form, theadditive's liquid component is present in an amount of not greater thanabout 50 weight percent; more typically of not greater than about 40weight percent; and even more typically in an amount of not greater thanabout 30 weight percent. All of the aforementioned weight percentagesare based on the total weight of the plastic additive system.

[0088] The ranges for the liquid component weight fraction in themultiple polymeric additive system for a latex, a suspension, a slurry,or a dispersion form is substantially the same as that for an emulsionform.

[0089] In the embodiment wherein the plastic additive system is in awet-cake form, the additive's liquid component is generally present inan amount of at least about 1 weight percent. Typically, when in thisform, the additive's liquid component is present in an amount of atleast about 5 weight percent; more typically of at least about 10 weightpercent; and even more typically in an amount of at least about 20weight percent. On the other hand, when in the wet-cake form, theadditive's liquid component is generally present in an amount of notgreater than about 60 weight percent. Typically, when in this form, theadditive's liquid component is present in an amount of not greater thanabout 50 weight percent; more typically of not greater than about 40weight percent; and even more typically in an amount of not greater thanabout 30 weight percent. All of the aforementioned weight percentagesare based on the total weight of the plastic additive system.

[0090] In the embodiment wherein the plastic additive system is in apaste form, the additive's liquid component is generally present in anamount of at least about 1 weight percent. Typically, when in this form,the additive's liquid component is present in an amount of at leastabout 5 weight percent; more typically of at least about 10 weightpercent; and even more typically in an amount of at least about 20weight percent. On the other hand, when in the paste form, theadditive's liquid component is generally present in an amount of notgreater than about 60 weight percent. Typically, when in this form, theadditive's liquid component is present in an amount of not greater thanabout 50 weight percent; more typically of not greater than about 40weight percent; and even more typically in an amount of not greater thanabout 30 weight percent. All of the aforementioned weight percentagesare based on the total weight of the plastic additive system.

[0091] With regard to the embodiments wherein the multiple polymericadditive system is in an emulsion form, the liquid component can containwater, surfactants, emulsifiers, stabilizers, ionic salts, acid or base,oligomeric species, and the like. Typically, the liquid componentcontains water. In an emulsion form, the solid component can contain anypolymer particle. Typically, polymer particles can be synthesized by anemulsion process or prepared by an alternative polymerization processand then subsequently emulsified. More typically, the solid componentcontains emulsion-made polymer particles containing acrylic-based ordiene-based polymers, or vinyl-halide-based polymers, ethylene-vinylacetate-based polymers, and the like. The solids weight fractions ofemulsion polymerized polymer particles prepared according to onespecific embodiment of the present invention are most typically in therange of from more than 40 to 75 weight percent.

[0092] The multiple polymeric additive system may also be in the form ofa suspension, a dispersion, and a latex, or mixtures thereof. In any oneof these forms, the liquid component can contain water, surfactants,emulsifiers, stabilizers, ionic salts, acid or base, oligomeric species,suspending agents such as polyvinyl alcohol and/or a variety of ionicand nonionic surfactants, and the like. Various types and specificexamples of these components are known to those skilled in the art. Theliquid component most typically contains water and a suspending agent.In a suspension form, the solid component can contain any solid additivesuitable as a plastic additive. Typically, the solid component containsemulsion-made polymer particles. More typically, the polymer particlescontain acrylic-based or diene-based polymers, or vinyl-halide-basedpolymers, ethylene-vinyl acetate-based polymers, and the like. Thesolids weight fractions of emulsion polymerized polymer particlesprepared according to one specific embodiment are most typically in therange of from more than 40 to 75 weight percent.

[0093] In a wet-cake form, the liquid component can contain one or moreof the same components as described for the dispersion, latex,suspension, or emulsion, with the addition of coagulating agents.Various coagulating agents are known to those skilled in the art forcoagulating particles dispersed in a fluid medium. Typical coagulatingagents include mineral salts, acids, bases, solvents, and non-solvents.Typically, the liquid component of a multiple polymeric additive systemin a wet-cake form will contain water and one or more coagulatingagents. In a wet-cake form, the solid component will contain the firstand second polymeric particles and may further contain precipitatedcoagulating agents. Solids weight fractions in wet-cake forms ofmultiple polymeric additive systems of this embodiment can be in therange of from 40 to 99 weight percent. Typically, the solids weightfraction in the wet-cake is less than 90 weight percent, and moretypically less than 80 weight percent. Wet-cake forms are most typicallyprovided by formation of a polymer particle slurry followed by removalof excess liquid, the liquid being typically water. Any method forremoving liquid from slurries as known to those skilled in the art canbe used. Accordingly, an increase in solids fraction is typicallyobserved during formation of a wet-cake from a slurry.

[0094] Preparation of multiple polymeric additive systems in a pasteform typically follows the preparation of a wet-cake. Paste formmultiple polymeric additive systems primarily differ from the wet-cakeform in that pastes are less friable than wet-cakes; whereas wet-cakeswill typically crumble when subjected to mechanical stress, pastes aremore likely to plastically deform than crumble when subjected tomechanical stress. In a paste form, the liquid component can contain oneor more of the same components as described for the wet-cake. In a pasteform, the solid component will contain the first and second polymericparticles and may further contain precipitated coagulating agents.Solids weight fractions in paste forms of multiple polymeric additivesystems of this embodiment can be in the range of from more than 40 to90 weight percent. Typically, the solids weight fraction in the paste isless than 80 weight percent, and more typically less than 75 weightpercent.

[0095] In the multiple polymeric additive system of the presentinvention, the solid component further can be at least one of thefollowing: waxes; pigments; opacifiers; fillers; exfoliated clays;toners; antistatic agents; metals; flame retardants; thermalstabilizers; co-stabilizers; co-stabilizers; antiozodants; cellulosicmaterials; impact modifiers; processing aids; lubricating processingaids; internal lubricants; external lubricants; oils; rheologymodifiers; powder flow aids; melt-flow aids; dispersing aids; UVstabilizers; plasticizers; fillers; glass fibers; optical modifiers;surface roughness modifiers; surface chemistry modifiers; adhesionmodifiers; surface hardeners; compatibilizers; diffusion barriermodifiers; stiffeners; flexibilizers; mold release agents; processingmodifiers; blowing agents; thermal insulators; thermal conductors;electronic insulators; electronic conductors; biodegradation agents;antistatic agents; internal release agents; coupling agents; flameretardants; smoke-suppressers; anti-drip agents; or colorants.Particularly preferred combinations of solid additive components andpolymeric additive components are in the following group: flow aids andimpact modifiers; impact modifiers and processing aids; processing aidsand blowing agents; processing aids and cellulosic fibers, lubricantsand cellulosic fibers, impact modifiers and cellulosic fibers,lubricating processing aids and cellulosic fibers, processing aids andlubricants and cellulosic fibers, impact modifiers and processing aidsand blowing agents; flow aids and impact modifiers and processing aids;lubricants and impact modifiers; stabilizers and impact modifiers;lubricants and stabilizers and impact modifiers; lubricants andprocessing aids; stabilizers and processing aids; lubricants andstabilizers and processing aids; oils and impact modifiers; fillers orother inorganics and processing aids; fillers or other inorganics andimpact modifiers; clays and impact modifiers; clays and processing aids;biocides and impact modifiers; biocides and processing aids, and thelike.

[0096] The multiple polymeric additive systems of the present inventioncan be prepared by any suitable means. The specific means of preparationdepends, in part, on the form in which the multiple polymeric additivesystem will have prior to being incorporated into the polymericcomposition, and the make-up of the additive's liquid and solidcomponents. Included below are some specific examples of how to make amultiple polymeric additive system in accordance with the presentinvention, wherein the additive system is in an emulsion form, awet-cake form and a paste form.

[0097] In one specific embodiment of the present invention there isprovided a novel process for making a multiple polymeric additive systemwhich includes a liquid component and a solid component, wherein thesolid component includes polymeric additive particles. The novel processrequires at least the two steps of (a) providing an aqueous emulsionpolymerization reaction mixture comprising a first population of polymerparticles and a second population of polymer particles; and (b)polymerizing a first group of one or more ethylenically unsaturatedmonomers in the aqueous emulsion polymerization reaction mixture so thatat least one of said populations of polymer particles increases in meanparticle diameter. Although this process requires that after a portionof the first group of one or more ethylenically unsaturated monomers ispolymerized the mean particle diameters of the first and secondpopulations of polymer particles differ by at least 50 percent, it istypical that the mean particle diameters differ by at least 100 percent,and more typical that the mean particle diameters differ by at least 200percent. Although this process also requires that the total weightpercentage of the polymer particles in the aqueous emulsionpolymerization reaction mixture exceeds 40 weight percent, it is typicalthat the weight percentage of the polymer particles exceeds 45 weightpercent, and even more preferable that the weight percentage exceeds 50weight percent.

[0098] In another specific embodiment of the present invention there isprovided a novel process related to the previously described process formaking a multiple polymeric additive system. This novel process requiresat least the two steps of (a) providing an aqueous emulsionpolymerization reaction mixture comprising a first population of polymerparticles and a second population of polymer particles; and (b)polymerizing a first group of one or more ethylenically unsaturatedmonomers in the aqueous emulsion polymerization reaction mixture to forma third population of polymer particles, wherein after a portion of thefirst group of one or more ethylenically unsaturated monomers ispolymerized. Although this process requires that after a portion of thefirst group of one or more ethylenically unsaturated monomers ispolymerized the mean particle diameters of the first and secondpopulations of polymer particles differ by at least 50 percent, it ispreferably that the mean particle diameters differ by at least 100percent, more preferable that the mean particle diameters differ by 200percent. Although this process also requires that the total weightpercentage of the polymer particles in the aqueous emulsionpolymerization reaction mixture exceeds 40 weight percent, it ispreferable that the weight percentage of the polymer particles exceeds45 weight percent, and even more preferable that the weight percentageexceeds 50 weight percent.

[0099] It is within the purview of this invention that in these twoprocesses for making a multiple polymeric additive system, the first andsecond populations of polymer particles in the aqueous emulsionpolymerization reaction mixture of step (a) can be provided by adispersion combination of the first and second populations of polymerparticles, wherein the dispersion combination is formed by combiningseparate dispersions of the first and second populations of polymerparticles.

[0100] It is also within the purview of this invention that in these twoprocesses for making a multiple polymeric additive system, the first andsecond populations of polymer particles in the aqueous emulsionpolymerization reaction mixture of step (a) are provided by a dispersioncombination of the first and second populations of polymer particles,wherein the dispersion combination is formed by forming one of thepopulations of polymer particles in a dispersion of the other populationof polymer particles.

[0101] It is also within the purview of this invention that in these twoprocesses for making a multiple polymeric additive system, the first andsecond populations of polymer particles in the aqueous emulsionpolymerization reaction mixture of step (a) are provided by a dispersioncombination of the first and second populations of polymer particles,wherein the dispersion combination is provided by forming essentiallysimultaneously the first and second populations of polymer particles ina dispersion.

[0102] In the embodiment where there two populations of polymerparticles are present, it is within the purview of the present inventionthat both populations grow in size during step (b). Likewise, in theembodiment where a third population of polymer particles forms, it iswithin the purview of the present invention that at least one of thefirst and second populations of polymer particles grow in size duringstep (b), however it is possible that both the first and secondpopulations grow in size during step (b) during formation of the thirdpopulation of polymer particles. This can be done, when after making thesecond mode using the soap addition, more soap is added to make thethird population of polymer particles.

[0103] In another embodiment of the process for preparing a multiplepolymeric additive system, three seeds can be provided to the reactionmixture. One specific embodiment is where a third seed is added to thefirst two. Multi-populations of polymer particles can be prepared usingthree or more seeds. As more and more modes are added, the maximumsolids fraction for a flowable dispersion is theoretically expected toincrease.

[0104] Accordingly, it is also envisioned that in both of thesetwo-population and three-population embodiments for making a multiplepolymeric additive system, that at least one of the first and secondpopulations of polymer particles essentially does not grow in sizeduring step (b). This can be provided where one of the polymer particleis not soluble with monomer, e.g., highly crosslinked, or the polymer inthe particle is not soluble with the monomer. Alternatively, where therate of polymerization in one seed population is substantially fasterthan in a second seed population, then (for kinetic reasons) the secondpopulation would essentially not grow under these conditions.

[0105] As well, in the three-population process, it is furtherenvisioned to be within the purview of this invention that both thefirst and second populations of polymer particles essentially do notgrow in size during step (b). As discussed above, it is possible toprovide two populations of polymer particles which do not grow in size,however the addition of extra soap results in make an additional one ormore modes which can grow in size. Alternatively, an independent modecan be prepared using a large swollen particle and smaller emulsionpolymer particles so that independent polymerization in two differentmodes result. Other combinations of growing and non-growing polymerparticles can be envisioned for providing various populations of polymerparticles.

[0106] In both of these processes for making a multiple polymericadditive system having either two and three particle populations, it isenvisioned that the mean particle diameter of the first and secondpopulations of polymer particles is typically at least 10 nm, preferablyat least 30 nm, and most preferably at least 50 nm. Likewise, it isenvisioned that the mean particle diameter of the first and secondpopulations of polymer particles is typically at most 50,000 nm,preferably at most 15,000 nm, and most preferably at most 1,000 nm.

[0107] In both of these processes for making a multiple polymericadditive system having either two and three particle populations, it isalso envisioned that the weight ratio of the first population of polymerparticles to the second population of polymer particles are in the rangeof from 10:90 to 90:10. Generally for impact modifiers, the smallerpopulation is provided at a weight fraction typically in the range offrom 40% to 60%.

[0108] In both of these processes for making a multiple polymericadditive system having either two and three particle populations, thechemical compositions of the polymer particles in the first and secondpopulations are essentially different, but they may also be physicallythe same or different. An example of physical differences is wherein theethylenically unsaturated monomers form a polymer in step (b) having aTg according to the Fox equation of less than 25° C., which is typicalfor forming rubbery polymers. In contrast, in the present invention formaking a multiple polymeric additive system, the ethylenicallyunsaturated monomers form a polymer in step (b) having a Tg according tothe Fox equation of at least 25° C., which is typically characteristicof forming hard polymers. For providing polymer Tg less than 25° C.,typical monomers include: C1 to C18 alkyl acrylates such as butylacrylate, ethyl acrylate, 2-ethylhexyl acrylate; diene monomers; vinylacetate monomers; and copolymers thereof, and the like. For Tg greaterthan 25° C., typical monomers include: C1-C4 alkyl methacrylates; vinylaromatic monomers, acrylonitrile monomers, and copolymers thereof, andthe like. One skilled in the art can combine these monomers in variousratios for the purposes of preparing “hard” versus “soft”, and “brittle”versus “rubbery” polymer phases in one or more specific embodiments ofthe two polymeric additive particles.

[0109] It is further envisioned that in the present invention for makinga multiple polymeric additive system, both of the processes for makingtwo-, and three-particle populations may further contain a third step(c), which involves polymerizing a second group of one or moreethylenically unsaturated monomers in the presence of at least the firstand second population of polymer particles to provide a polymer adjacentto the surfaces of the polymer particles of the first and secondpopulations. In this additional step, it is envisioned that the secondgroup of one or more ethylenically unsaturated monomers can be the sameas or different than the first group of one or more ethylenicallyunsaturated monomers. In varying the properties of impact modifiers, forexample, one typically controls: degree of crosslinking in the corerubber; degree of graft-linking of polymer shells to underlying phases,such as the core; molecular weight of the polymer shell; and morphology(e.g., a shell or diffusion of particles into the core). In thisadditional step, it is also envisioned that the second group of one ormore ethylenically unsaturated monomers is polymerized after at least aportion of the first group of one or more ethylenically unsaturatedmonomers is polymerized. It is within the purview of this invention thatany combination of cores, shells, interpolymer phases, monomers,crosslinkers, and graftlinkers is possible for preparing polymericadditive particles.

[0110] In these embodiments wherein a second group of ethylenicallyunsaturated monomers are polymerized, it is within the purview of thepresent invention that the second group of monomers is polymerized afteressentially all of the first group of monomers are polymerized. Thisstep is useful for controlling morphology.

[0111] As a specific embodiment of the present invention for making amultiple polymeric additive system, it is envisioned that the firstgroup of monomers forms a rubbery core polymer and the second group ofmonomers forms a hard shell polymer. Rubbery core monomers include, forexample, alkyl acrylates. The rubbery core monomers may also include oneor more crosslinkers in the amount of about 1% to 5% based on monomers.In the case where the rubbery monomers include diene monomers,crosslinker may not be necessary as diene monomers tend toself-crosslink. Such self-crosslinking depends on the reactionconditions and post-reaction conditions as known in the art. The hardshell monomers may contain, as a specific example, methyl methacrylateand styrene. Although the rubber core polymer component as justdescribed in certain polymeric additives should be at least 50%, it isfurther desirable that the rubbery core polymer is greater than 70%, andin certain cases it is desirable that the rubbery component is presentin amounts of from 80 to 100 weight percent, said weight percentagebeing based on the total weight of the rubbery core and hard shellpolymers. It is also envisioned that the polymeric impact modifierpolymer particle has no shell polymer, e.g., using a 100% rubbery coreis possible, such as a crosslinked alkyl acrylate rubbery polymerparticle, for impact modifying PVC.

[0112] Oftentimes, in the present invention for making core/shell typepolymer particles, the second group of monomers can be added to thereaction mixture before the first group have been completelypolymerized, so that both monomers from the first and second groups aresimultaneously present in the reaction mixture. In this situation, it isalso envisaged that while the second group of monomers do notnecessarily copolymerize with the unpolymerized monomers from the firstgroup, it is oftentimes desirable that at least a portion of the secondgroup of monomers copolymerize with a portion of the unpolymerizedmonomers from the first group of monomers. Likewise, it is oftentimesdesirable that at least a portion of the second group of monomerscopolymerizes with essentially all of the unpolymerized monomers fromthe first group of monomers. This process may be controlled by comparingthe reactivity ratios of monomers as known in the art. This process canbe controlled to prepare either separate, alternating, blocky, or randomcopolymers as known in the art.

[0113] With regard to one specific example wherein the multiplepolymeric additive system is in an emulsion form, reactants (e.g.,monomers, initiators, emulsifiers, and optional chain transfer agents,etc.) are typically combined in a reactor with a liquid medium (e.g., anaqueous medium) to form a mixture. Thereafter, and/or simultaneouslytherewith, the mixture is reacted while in the presence of the liquidmedium. The reactants can be added slowly (gradually, as in a semi-batchprocess), over time, continuously, or quickly as a “shot” (batch) intothe reactor. Emulsion polymerization techniques for preparing polymerparticles are typically carried out in a suitable reactor wherein thereactants (monomers, initiators, emulsifiers, pH buffers, salts, acids,bases, optional chain transfer agents, and the like) are suitablycombined and mixed, and reacted in an aqueous medium, and wherein heatmay be transferred in to, and away from, the reaction zone. Thereactants can be added slowly (gradually, as in a semi-batch process)over time, quickly as a “shot” (batch), or continuously into thereactor.

[0114] In another specific example wherein the multiple polymericadditive system is in an emulsion form, the process encompasses at leastthe following steps. First, an aqueous emulsion polymerization reactionmixture is provided which includes a first and second population ofpolymer particles. These polymer particles as provided for in thereaction mixture are typically referred to by those skilled in the artof emulsion polymerization as “polymer seed particles”, “seedparticles”, or simply “seed”. It is also known to those skilled in theart that polymer particles formed in one step may be further used asseed particles in another step. Then, a first group of one or moreethylenically unsaturated monomers is polymerized in the aqueousemulsion such that: the mean particle diameters of the first and secondpopulations of polymer particles differ from each other by at least 50percent, and the total weight percentage of the polymer particles in theaqueous emulsion polymerization reaction mixture exceeds 40 weightpercent. After the polymer particle populations are provided for in areaction mixture, monomers are subsequently added in order to providefor “grow out” of one or both of the polymer seed particle populations.In this invention it is envisioned that when both seed particlepopulations “grow out”, this grow-out can occur simultaneously or atdifferent times.

[0115] Methods for polymer seed grow out are well known in the art.These methods are useful for preparing polymer particles having aparticle size in the range of from 10 nm to 1,500 nm. Typically, monomerand initiator are added to the reaction mixture at conditions toinitiate and polymerize monomer as it is added to the reaction mixture.Typically, the polymer particle size will increase with increasing seedsize. Accordingly, the seed size range can vary from 10 nm to 1,500 nm.In this embodiment, the seed size is typically at least 30 nm, moretypically at least 50 nm, and most typically at least 70 nm.

[0116] One specific example of providing an emulsion polymer of at leasttwo populations of polymer particles is where a single polymer seed andexcess soap is provided into the reaction mixture so that upon additionof monomer, a second population of polymer particles is formed. In thisexample, the amount of excess soap that is required to form the secondpopulation of polymer particles will vary with the type of soap, andconditions of the reaction media to form micelles. Subsequent orsimultaneous addition of monomer and initiator into the reaction mixturethereby forms the second population of polymer particles. This isfollowed by one or more additional “grow out” steps as described above.Further steps providing additional populations of seed particlesfollowed by grow-out are also envisioned within the scope of the presentinvention.

[0117] Another specific example is where seeds of two or more sizes areprovided, followed by a swelling process. Seeds of two or more sizes canbe provided as previously described. The swelling process typicallyinvolves adding emulsified monomers, or mixtures of monomers to seedparticles present the aqueous reaction media so that the seed particlesswell with monomer prior to forming polymer. The initiator is typicallypresent in the monomer mixture or subsequently added to the reactionmixture. Then, the monomers are polymerized after swelling. By thisprocess, there is no limitation to the upper size of the mean polymerdiameter.

[0118] Another specific example of forming two populations of polymerseed particles is provided where polymer seed particles of a single modeare partially agglomerated (i.e. “microagglomerated”, as known in theart). In this example, the seed particles agglomerate to differentextents, thereby forming multimodal populations of seed particles.Although such microagglomeration steps typically require polymerparticle solids levels less than 40%, it is envisioned that furtherswelling and/or grow-out steps applied to such microagglomerated seedparticles will result in formation of multiple polymeric additivesystems having solids fractions greater than 40%.

[0119] Preparing a combination of two polymer particle populations whichdiffer in composition and/or particle size can be provided using twoseeds which vary in size and/or composition. The final size of theparticles depend on the starting size and the starting composition ofthe seeds. If the seeds are the same compositions, then they typicallygrow and/or swell at similar rates of “mass uptake”. The term “massuptake” refers to the increase in mass of the polymer particles arisingfrom additional monomer and/or polymer.

[0120] Rates of mass uptake may be estimated according to polymerthermodynamic principles known to those skilled in the art. For example,if the seed compositions are different, then the rate of mass uptakewill generally be different. If the seeds are same composition butdifferent size, then the larger seed particles will generally remainlarger during mass uptake. As well, increasing the molecular weight ofthe polymer in the seeds generally provide for smaller final polymerparticles. Generally, these and other guidelines for controlling polymerparticle size are estimable via equilibrium swelling calculationsaccording to the principles of polymer thermodynamics and reactionkinetics as known to those skilled in the art.

[0121] Typically, particle sizes in the range of from 100 nm to 50,000nm can be provided using the swelling process. More typically, polymerparticles in the range of from 1,000 nm to 50,000 nm are readilyprepared by a swelling process.

[0122] It is also envisioned that one or more of these methods may becombined to prepare the multiple polymeric additive systems of thepresent invention. Those skilled in the art would be able to readilydetermine which specific process best suits their needs after readingthis specification.

[0123] In yet another specific example wherein the multiple polymericadditive system is in an emulsion form, the process encompasses at leastthe following steps. First, an aqueous emulsion polymerization reactionmixture is provided which includes a first population and secondpopulation of polymer particles. Then, a first group of one or moreethylenically unsaturated monomers is polymerized in the aqueousemulsion such that a third population of polymer particles is formed.Formation of the third population can be provided by the addition ofexcess soap to form seed particles as described in a previousembodiment, or they can be added separately. The step of swelling and/orgrow-out of the first, second, and/or third population of polymerparticles subsequently follows according to the procedures described ina previous embodiment.

[0124] In another embodiment of the present invention, non-aqueouspolymerization is used to prepare the solid component containing a firstand second population of polymer particles. This can be provided for, byexample, using dispersion polymerization wherein a solvent, such as analcohol, is the reaction medium. The reaction medium is mixed with oneor more monomers, wherein the polymer is formed and may precipitate outof the solvent to form a first population of polymer particles.Subsequent steps of adding further monomer to form additionalpopulations of polymer particles are provided to form a multipleplastics additive system.

[0125] Inverse emulsion polymerization methods are also envisioned forpreparing polymer particles useful in multiple polymeric additivesystems. These methods, which are known to those skilled in the art,incorporate an aqueous phase which is dispersed in an organic phase. Inthis method, water-soluble monomers which prefer the aqueous phasepolymerize to form polymer particles dispersed in an organic phase.

[0126] Various methods for preparing populations of polymer particlesinclude solution polymerization, dispersion or suspensionpolymerization, microemulsion polymerization, miniemulsionpolymerization; jet-droplet polymerization; screen-dropletpolymerization, and the like. These various methods are useful forpreparing polymer particle dispersions having a mean particle diameterin the range of from 20 nm to 50,000 nm. Typically, the liquids presentin this method include water and/or organic solvents, the range and typeof each for these polymerization methods are known to those skilled inthe art.

[0127] These various methods for preparing populations of polymerparticles typically include one or more of the liquids in the followinggroup: monomers, solvents, non-solvents, chain transfer agents,initiators, soaps, buffer solutions, stabilizers to prevent polymerparticle coalescence, crosslinkers, graft linkers, aqueous phaseinhibitors for preventing polymerization in the aqueous phase, and thelike. Accordingly, the multiple polymeric additive systems of thepresent invention typically include one or more of these liquids.

[0128] In the multiple polymeric additive system of the presentinvention the compositions of the first and second populations ofpolymer additive particles are essentially compositionally different. Itis within the purview of the present invention that the first and secondpopulations are essentially compositionally different as long aspolymers in both populations share no more than about 85% by weight ofthe same type of polymeric units. Typically, the two populations will beessentially compositionally the same if they share no more than about90%, more typically no more than 95%, by weight of the same type ofpolymeric units.

[0129] One specific embodiment of this invention is where solidcomponent of the multiple polymeric additive system contains one or moreadditional populations of polymeric additive particles. In thisembodiment, the one or more additional populations of polymeric additiveparticles may be compositionally essentially the same as or differentthan that of the first and second populations.

[0130] Examples of polymer particle compositions which are envisionedmay be derived from, but are not limited to, the following polymercompositions: polymers derived from diene, diene/vinyl aromatic, orcrosslinked diene/vinyl aromatic monomers; polymers derived from (C1 toC20) alkyl (meth)acrylates; copolymers derived from (C1 to C20) alkyl(meth)acrylates, (e.g. 2-ethylhexyl acrylate mixed with a butylacrylate); copolymers derived from (C1 to C20) alkyl (meth)acrylateswhich vary in comonomer ratio; copolymers derived from (C1 to C20) alkyl(meth)acrylates which vary in comonomer ratio to provide for differencesin glass transition temperatures, e.g., high Tg (greater than 75 C.)polymer and low Tg polymer and (less than 0 C.); ethylene-vinylacetate(“EVA”) type copolymers; chlorinated polyethylene (“CPE”); polymersderived from olefins; copolymers or blends containing copolymers derivedfrom (C1 to C20) alkyl (meth)acrylates mixed with EVA or chlorinatedpolyethylene (“CPE”) or polyolefins.

[0131] Examples of different polymer particle compositions which areenvisioned include wherein the polymer particles contain: an impactmodifier and a processing aid, e.g., polymer 1 containing greater than50% low Tg component, polymer 2 containing greater than 50% high Tgcomponent; two processing aids (“PA”), e.g., two substantiallyuncrosslinked polymers, with greater than 50% high Tg component; alubricating PA plus a PA, e.g., uncrosslinked polymers, at least onegreater than 50% high Tg polymer, the other derived from butylacrylateand styrene). In addition, acrylonitrile (“AN”) containing polymers,typically styrene-AN based processing aids and/or thebutadiene-styrene-AN impact modifiers are combinable in the presentinvention. Combinations of polyolefin and fluoropolymer particles, bothof which can be made by solution, are also combinable.

[0132] One specific embodiment of different types of polymeric additiveparticles is where the first and second populations are useful as impactmodifiers and the additional one or more populations are useful asprocessing aids. Another specific embodiment of different types ofpolymeric additive particles is where the first and second populationsare useful as processing aids and the additional one or more populationsare useful as impact modifiers. Combinations of various polymericadditives are readily envisioned to those skilled in the art.

[0133] Another specific embodiment wherein the multiple polymericadditive system contains different compositions of polymer particles iswhen a balance of impact efficiency and UV resistance is desired. Inthis case, different compositions can be provided by the followingprocess: emulsion blend of a diene-derived impact modifier with anacrylic-derived impact modifier. For the purposes of preparing amultiple polymeric additive system containing a solids component inexcess of 40 weight percent, it is envisioned to start with twodiene-type polymer seed particles varying in diameter and compositionfor preparing the first and second populations of polymer particlesvarying at least 50% in diameter. Diene-type monomers are subsequentlypolymerized in the presence of these seed particles to form the firstand second populations of diene-derived polymer particles. Additionalseed particles are either added to or formed in the reaction mediacontaining the first and second populations of diene-derived polymerparticles. Subsequently, polymerization of another type of one or moremonomers, such as a (C1-C20) alkyl (meth)acrylates form on or in theadditional seed particles. Following this specific embodiment, one couldmake a methacrylate-butadiene-styrene (“MBS”)-type impact modifierfurther containing an acrylic processing aid at a solids concentrationof greater than 40%.

[0134] In one embodiment of preparing a multiple polymeric additivesystem in which a polymeric component is modified by use of the multiplepolymeric additive system, the multiple polymeric additive systems whichare typically used in this process can have a solid component containingone or more additional populations of polymer particles which aredifferent than the first and second populations of polymer particles.These differences can arise from physical property differences. Examplesof physical property differences include: size, shape, glass transition,hardness, refractive index or other optical properties, thermal or UVstability, and the like. Polymer particle differences may also arisefrom differences in chemical properties. Examples of chemical propertydifferences include: monomer compositions, surface activity, copolymercomposition and sequencing, ratio and composition of different polymerphases within the particles, molecular weight, presence of functional orreactive groups on the polymer, morphology, and the like.

[0135] In another embodiment of preparing a multiple polymeric additivesystem, any of the one or more of these liquids can be readilyincorporated into the liquid component of the polymeric additive bydirect addition, emulsification or suspension by suspending agents inwater or a suitable solvent, and optionally applying shear. The amountof these liquids in the liquid component can be in the range of from 0to 100 weight percent; typically from 0 to 20 weight percent; mosttypically from 0 to 10 weight percent of the liquid component. Theamount of emulsion stabilizers can be in the range of from 0 to 100weight percent; typically from 0 to 5 weight percent; most typicallyfrom 0.01 to 2 weight percent of the liquid component. The amount ofdefoamers can be in the range of from 0 to 100 weight percent; typicallyfrom 0 to 10 weight percent; most typically from 0 to 5 weight percentof the liquid component.

[0136] Depending on the desired end use and properties, the amount ofliquid components, such as plasticizers, organic solvents, alcohols,esters biocides, UV stabilizers, leveling agents, lubricants, oils,dyes, rheology modifiers, thermal stabilizers, antiozodants, and or moldrelease agents, can be in the range of from 0 to 100 weight percent;typically from 0 to 20 weight percent; and most typically from 0 to 10weight percent of the liquid component. When two or more of theaforementioned liquids are present in the liquid component of themultiple polymeric additive system then it is apparent that their totalweight fraction can be no higher than 100% based on the total weight ofthe liquid component.

[0137] In one specific embodiment of the process for preparing amultiple polymeric additive system, a dispersion of solid or liquidlubricant particles can be incorporated in to the multiple polymericadditive system by emulsifying the solid or liquid lubricant in water orother non-solvent with a surfactant and shear mixing. The lubricantemulsion is then mixed into the multiple polymeric additive system. In asimilar fashion, the solid or liquid lubricant may be emulsified in anemulsion, latex, dispersion, or suspension containing one or more othercomponents of the multiple polymeric additive system as anotherembodiment. One specific example is where the lubricant may beemulsified by adding a surfactant and shear mixing in a multipleemulsion containing the two or more populations of polymeric additiveparticles. In a similar fashion, because thermal stabilizers are mostlyprovided as liquids, oils, solids which are typically non-soluble inwater, thermal stabilizers may also be emulsified and added to themultiple polymeric additive system according to these procedures.

[0138] In another embodiment of the process for preparing a multiplepolymeric additive system, the liquid component may contain awater-soluble thermal stabilizer by providing a suitably high polarityreactive ligands which react to tin or other metals known in the art ofstabilization. High-polarity character is provided to the ligands bytypically providing short alkyl groups, which typically have lowmolecular weight. Examples include mercapto ethanol or thio glycolicacid.

[0139] In another specific embodiment of the process for preparing amultiple polymeric additive system, stabilizers and lubricants may beincorporated into the liquid component with organic solvents as theliquid phase. Because stabilizers and lubricants typically are insolublein water, they may be incorporated into the liquid component of themultiple polymeric additive system by using organic solvents andoptionally soap to help dissolve or disperse them. In this regard,various solvent/oil/aqueous/soap combinations may be employed to providedispersions or solutions of one or more additives, such as stabilizersand lubricants, in the liquid component of the multiple polymericadditive system.

[0140] In another specific embodiment of the process for preparing amultiple polymeric additive system, various liquid and solid components,such as stabilizers and co-stabilizers, may be microencapsulated bypolymerizing an encapsulating polymer via suspension or emulsionpolymerization in the presence of an emulsion, suspension, dispersion,or slurry of stabilizer particles as provided in the process describedabove.

[0141] Co-stabilizers are also important and include but are not limitedto epoxidized soybean oil (“ESO”), phosphite-based organic compounds,betadiketones, and certain mineral fillers. The certain mineral fillerswhich function as co-stabilizers typically include hydrotalcites whichare insoluble solids in most liquids. Co-stabilizers are typically usedalong with various tin-based, and mixed metal-based and lead-basedthermal stabilizers and the like as known in the art. Co-stabilizerstypically scavenge hydrochloric acid that forms during degradation ofPVC. Typically, this scavenging occurs by the co-stabilizer chelatingwith the PVC's degradative by-products. Other co-stabilizers includeanti-oxidants which arrest oxidative degradation.

[0142] Other stabilizers which can be incorporated in the multiplepolymeric additive system's liquid component include uracil derivatives,and the like. Typically, 0-10% by weight of these nitrogen-containingstabilizer components are useful to reduce degradation in polymericresins, such as PVC. Various uracil derivatives can be incorporated inthe present invention as other stabilizing agents as described above.Examples of such uracil derivatives include: 2-phenylindoles;aminocrotonates; N-substituted maleimides; uracil; the1,3-dialkyl-6-amino-uracil derivatives described in German Patent19,741,778, and pyrollodiazinediones described in Australian Patent AppAU-A48232-96.

[0143] In another specific embodiment of the process for preparing amultiple polymeric additive system, various blowing agents for foamingpolymeric compositions can also be incorporated into the multiplepolymeric additive system. Various blowing agents are known in the artand can be used in the invention herein. Typical blowing agentsthermally degrade at elevated temperatures and form a gas. When blendedinto molten polymer, the production of gas causes the molten polymer toform a foam or cellular structure. Typical blowing agents include azocompounds and sodium borohydride, both of which can be used in liquidmedium and thereby added to the multiple polymeric additive system'sliquid component.

[0144] In another specific embodiment of the process for preparing amultiple polymeric additive system, the liquid component containsessentially no water. One specific example for providing this embodimentis where a portion of the solid component of the multiple polymericadditive system is provided by a solution polymer and a portion of theliquid component is provided by the solvent used in preparing thesolution polymer. Another example is wherein polymer particles preparedin aqueous media are first dried then redispersed in a nonaqueousliquid. Any of the various methods know in the art of providingpolymeric particles substantially devoid of water can be used in thisembodiment of the invention.

[0145] In another embodiment for preparing a multiple polymeric additivesystem, the polymeric additive particles may contain at least twodifferent polymeric additives selected from the following group: impactmodifiers; processing aids; lubricating processing aids; opticalmodifiers; hollow spheres; waxes; toners; antistatic agents; cellulosicmaterials; oils; rheology modifiers; powder flow aids; melt-flow aids;dispersing aids; plasticizers; fillers; optical modifiers; surfaceroughness modifiers; surface chemistry modifiers; adhesion modifiers;surface hardeners; compatibilizers; diffusion barrier modifiers;stiffeners; flexibilizers; mold release agents; processing modifiers;blowing agents; thermal insulators; thermal conductors; electronicinsulators; electronic conductors; biodegradation agents; internalrelease agents; coupling agents; flame retardants; smoke-suppressers.These other additives can be incorporated by the following processes:Direct addition of the additive into the polymer liquid system,emulsification or suspension of the second additive into the polymericliquid additive, copolymerization or encapsulation, of the secondadditive component during the preparation of the polymeric liquidadditive, polymerization of the liquid additive in the presence of thesecond additive to form an in-situ blend, addition of the secondadditive during a subsequent blending or drying or isolation step.

[0146] In another embodiment for preparing a multiple polymeric additivesystem, the polymeric additive particles can be spherically-shaped.Processes for preparing spherical shaped particles include: emulsion,solution, suspension, dispersion, mini-emulsion, micro emulsion. Otherparticles that are not spherical in shape which are envisioned include:multilobe, raspberry, dumbbell, high aspect ratio ellipsoidal particles,and fibers, and the like. Such non-spherical particles can be madeaccording to processes known in the art.

[0147] Another embodiment of this invention encompasses novel polymericcompositions that include a polymeric component and a polymeric additivecomponent. In this embodiment, the novel polymeric composition isprepared by a process which includes the step of forming a blend of atleast the polymeric component and a multiple polymeric additive system,wherein the multiple polymeric additive system includes a liquidcomponent and a solid component. The multiple polymeric additivesystem's solid component, in turn, includes at least two populations ofpolymeric additive particles. These polymer particle populations areessentially compositionally different. The solids weight fraction of themultiple polymeric additive system is also more than 40% based on thetotal weight of the multiple polymeric additive system. It is within thepurview of the process for preparing the polymeric compositions that oneor more additional populations of polymer particles may also be presentin the solid component of the multiple polymeric additive system. Theone or more additional populations of polymer particles may differ withregard to at least one of the following: the property which they willimpart to a polymeric composition into which they can be added, theirsize, their chemical composition, their physical state and/or theirshape.

[0148] Another embodiment of the present invention encompasses making apolymeric composition comprising a polymeric component and a multiplepolymeric additive system. In this embodiment, the process includes thestep of (I) contacting the polymeric component with a multiple polymericadditive system to form a mixture, wherein the multiple polymericadditive system includes a) a liquid component, and b) a solidcomponent. In this embodiment, the solid component includes at leastpolymeric additive particles, wherein the polymeric additive particlesincludes at least (i) a first population of particles, and (ii) a secondpopulation of particles, wherein the compositions of the polymerparticles in the first and second populations are essentially different.While the weight percentage of the solids component of the multiplepolymeric additive system in this embodiment is typically more than 40weight percent, of the total weight percentage of the multiple polymericadditive system, the solids weight percentage can be even greater.

[0149] In this embodiment of the invention, the process also includesthe step of (II) removing at least a portion of the liquid componentfrom the mixture. Any of the water removal methods known in the art ofpolymer processing may be used. These include dewatering at variouspoints in the processes (e.g. dewatering with the polymeric component,dewatering prior to blending, dewatering during the blending, dewateringin the extruder and so forth are typical operations used to removewater. Typically the liquid is being volatilized by heat to affectremoval. Various filtration methods such as ultrafiltration, microfiltration, reverse osmosis, and the like can also be used forincreasing the solids concentration of flowable forms of the multiplepolymeric additive system. Flowable forms of the multiple polymericadditive system include liquid, solution, emulsion, latex, suspension,slurry, dispersion, and the like.

[0150] Various other embodiments of making a polymeric composition byblending a polymeric resin with the multiple polymeric additive system,are envisioned in the following list of modifications to the process.Further details are provided in this document:

[0151] In step (I) the liquid component may be present in an amount ofat least 1 weight percent, said weight percentage being based on thetotal weight of the multiple polymeric additive system.

[0152] In step (I) the liquid component may be present in an amount ofless than 60 weight percent, said weight percentage being based on thetotal weight of the multiple polymeric additive system.

[0153] In step (I) the solid component may be present in an amount ofmore than 40 weight percent, said weight percentage being based on thetotal weight of the multiple polymeric additive system.

[0154] In step (I) the polymeric additive particles are present in anamount of at most 99 weight percent, said weight percentage being basedon the total weight of the multiple polymeric additive system.

[0155] In step (I) the liquid component may contain at least 5 weightpercent water, said weight percentage being based on the total weight ofthe multiple polymeric additive system's liquid component.

[0156] In step (I) the liquid component may contain at most 100 weightpercent water, said weight percentage being based on the total weight ofthe multiple polymeric additive system's liquid component.

[0157] In step (I) the liquid component may contain at least one liquidfrom the following group: water; organic solvents; alcohols; esters;plasticizers; emulsion stabilizers; defoamers; leveling agents;biocides; UV stabilizers; lubricants; oils; dyes; rheology modifiers;thermal stabilizers; co-stabilizers; antiozodants; mold release agents,oligomers, monomers, and the like and combinations thereof.

[0158] In step (I) the liquid component may contain essentially nowater.

[0159] The polymeric additive particles contain at least one polymericadditive selected from the following group: impact modifiers; processingaids; lubricating processing aids; optical modifiers; hollow spheres;waxes; toners; antistatic agents; cellulosic materials; oils; rheologymodifiers; powder flow aids; melt-flow aids; dispersing aids;plasticizers; fillers; optical modifiers; surface roughness modifiers;surface chemistry modifiers; adhesion modifiers; surface hardeners;compatibilizers; diffusion barrier modifiers; stiffeners; flexibilizers;mold release agents; processing modifiers; blowing agents; thermalinsulators; thermal conductors; electronic insulators; electronicconductors; biodegradation agents; internal release agents; couplingagents; flame retardants; smoke-suppressers.

[0160] The polymeric additive particles may be spherically-shaped.

[0161] The first population of polymeric additive particles may have amean particle diameter in the range of from 10 nm to 50,000 nm.

[0162] The second population of polymeric additive particles may have amean particle size distribution ranging from about 10 nm to about 50,000nm.

[0163] The multiple polymeric additive system may be in the form of atleast one of the following: an emulsion, suspension, dispersion, latex,paste, pellet, powder, or a wet-cake.

[0164] The solid component of the multiple polymeric additive system mayfurther contain at least one of the following: waxes; pigments;opacifiers; fillers; exfoliated clays; toners; antistatic agents;metals; flame retardants; thermal stabilizers; co-stabilizers;antiozodants; cellulosic materials; impact modifiers; processing aids;lubricating processing aids; internal lubricants; external lubricants;oils; rheology modifiers; powder flow aids; melt-flow aids; dispersingaids; UV stabilizers; plasticizers; fillers; optical modifiers; surfaceroughness modifiers; surface chemistry modifiers; adhesion modifiers;surface hardeners; compatibilizers; diffusion barrier modifiers;stiffeners; flexibilizers; mold release agents; processing modifiers;blowing agents; thermal insulators; thermal conductors; electronicinsulators; electronic conductors; biodegradation agents; antistaticagents; internal release agents; coupling agents; flame retardants;smoke-suppressers; anti-drip agents; or colorants.

[0165] The polymeric component may contain at least one of thefollowing: polyamides, aromatic polyesters, polycarbonate,styrene-acrylonitrile copolymers, styrenic resins, methyl methacrylatecopolymers, polyolefins, polyvinyl halides, polyamides, epoxy resins,polyacetals, polyurethanes, and thermoset resins, poly ether ketones,polyarylates, polysulfones, polyimides, and the like, and copolymers,grafts, and blends thereof.

[0166] When forming the blend, the polymeric component may be initiallyin a liquid phase.

[0167] When forming the blend, the polymeric component may be initiallyin a solid phase.

[0168] After forming the blend, the polymeric component may be in aliquid phase.

[0169] After forming the blend, the polymeric component may be in asolid phase.

[0170] When forming the blend, the polymeric component reacts with atleast a portion of the multiple polymeric additive system's liquidcomponent.

[0171] When forming the blend, the polymeric component reacts with atleast a portion of the multiple polymeric additive system's solidcomponent.

[0172] When forming the blend, the polymeric component does not reactwith either the multiple polymeric additive system's solid component orthe polymeric additive's liquid component.

[0173] When forming the blend, the at least a portion of the multiplepolymeric additive system's solid component reacts with at least aportion of the polymeric additive's liquid component.

[0174] When forming the blend, the multiple polymeric additive system'ssolid component does not react with the polymeric additive's liquidcomponent.

[0175] When forming the blend, at least a portion of the multiplepolymeric additive system's solid component forms a by-product.

[0176] When forming the blend, the at least a portion of the multiplepolymeric additive system's liquid component forms a by-product.

[0177] When forming the blend, neither the multiple polymeric additivesystem's solid component nor the polymeric additive's liquid componentforms a by-product.

[0178] After forming the blend, the blend may contain at least a portionof the polymeric additive's liquid component.

[0179] After forming the blend, the blend may be formed into a productcomprising at least a portion of the polymeric additive's liquidcomponent.

[0180] After forming the blend, the blend may be formed into a productcomprising essentially none of the polymeric additive's liquidcomponent.

[0181] After forming the blend, the blend may contain essentially noneof the polymeric additive's liquid component.

[0182] The polymeric composition further may contain at least a secondmultiple polymeric additive system.

[0183] When forming the blend, at least a portion of the second multiplepolymeric additive system may react with at least a portion of the firstmultiple polymeric additive system.

[0184] When forming the blend, essentially none of the second multiplepolymeric additive system may react with the first multiple polymericadditive system.

[0185] When forming the blend, at least a portion of the second multiplepolymeric additive system may react to form a by-product.

[0186] When forming the blend, essentially none of the second multiplepolymeric additive system may react to form a by-product.

[0187] The polymeric composition may contain at least one of thefollowing: waxes; pigments; opacifiers; fillers; exfoliated clays;toners; antistatic agents; metals; flame retardants; thermalstabilizers; co-stabilizers; antiozodants; cellulosic materials; impactmodifiers; processing aids; lubricating processing aids; internallubricants; external lubricants; oils; rheology modifiers; powder flowaids; melt-flow aids; dispersing aids; UV stabilizers; plasticizers;fillers; optical modifiers; surface roughness modifiers; surfacechemistry modifiers; adhesion modifiers; surface hardeners;compatibilizers; diffusion barrier modifiers; stiffeners; flexibilizers;mold release agents; processing modifiers; blowing agents; thermalinsulators; thermal conductors; electronic insulators; electronicconductors; biodegradation agents; antistatic agents; internal releaseagents; coupling agents; flame retardants; smoke-suppressers; anti-dripagents; or colorants.

[0188] After forming the blend, the blend may be formed into an article.

[0189] After forming the blend, the blend may be used to form anarticle.

[0190] The polymeric component may be in powder form.

[0191] The polymeric component may be in the form of wet-cake.

[0192] The polymeric component may be in the form of a melt.

[0193] The multiple polymeric additive system may be in the form of anemulsion.

[0194] The multiple polymeric additive system may be in the form ofcoagulated slurry or wet-cake.

[0195] The polymeric additive particles may contain at least 10 percentby weight of a rubbery core.

[0196] In polymeric additive particles containing a rubbery core, therubbery core may exceed 70 percent by weight of the graft copolymer.

[0197] In polymeric additive particles containing a rubbery core, therubbery core may be from 90 to 95 percent by weight of the graftcopolymer.

[0198] The dry weight ratio of multiple polymeric additive system topolymeric component polymer may be in the range of from 0.1:99.9 to50:50.

[0199] In one process for preparing a polymeric composition in which apolymeric component is modified by use of the multiple polymericadditive system of the present invention, the polymeric component and atleast one multiple polymeric additive system are blended to form thepolymeric composition. The blending step can occur by one or more of thefollowing processes: blending of the multiple polymeric additive systeminto a polymeric component. Typically, the multiple polymeric additivesystem will have a flowable form such as an emulsion, fluid, latex,slurry, dispersion, or suspension. The blending step may occur duringany of the stages of preparation of the polymeric component. Thesestages include synthesis and/or subsequent isolation and compounding;blend mixing of the multiple polymeric additive system into thepolymeric component, the polymeric component typically having a solidform. A variety of solid forms of the polymeric component includes:powder, granules, and pellets. The polymeric component may also have aflowable form such as an emulsion, fluid, latex, slurry, dispersion, orsuspension.

[0200] In a specific embodiment for preparing the polymeric compositionby blend mixing the polymeric component with the multiple polymericadditive system, blend mixing may occur with or without the use ofmechanical agitation and heat. Blend mixing may occur by addition of themultiple polymeric additive system directly to the polymeric componentin the melt state. The melt state may occur during a final meltprocessing step for fabrication or during an intermediate meltprocessing step to prepare polymer blends for subsequent processing andfinal shaping. A typical process is where multiple polymeric additivesystem is added to the polymeric component, the polymeric componenthaving a powder form. This is followed by shear agitation and optionalheat treatment to provide a polymeric composition in the form of apowder blend. The resulting powder-form polymeric composition issuitable for melt processing by any of the standard melt processingtechniques known in the art of polymer and plastics processing. Theseprocessing techniques typically include extrusion, kneader compoundingor static mixing, injection molding, blow molding, tbermoforming,calendering, and the like. Heat can be supplied by mechanical frictionusing, for example, thermokinetic blenders, kneaders or extruders, or byelectrical means, say, in an electrically heated device. Additionally,the use of vacuum to remove low-boiling liquid components like water,can often be done effectively.

[0201] Another way that the blending step may be accomplished is by theaddition of the multiple polymeric additive system to the polymericcomponent while the polymeric component is being synthesized. As aspecific example, multiple polymeric additive systems containing waterin the liquid component can be readily blended with aqueous-preparedpolymeric components in the polymeric component reaction vessel,suitable container, or in a suitable mixing device. Subsequently, thepolymeric composition can be dried using the same or different dryingequipment used for the polymeric component. Accordingly, this embodimentenvisions that the polymeric component and the polymer additive systemmay be blended and dried together.

[0202] In another embodiment of preparing a polymeric composition inwhich a polymeric component is modified by use of the multiple polymericadditive system, the polymer particles in the solid component may havethe following physical properties: high fraction of low Tg polymer, highmolecular weight, refractive index close to or equivalent to that of thepolymer. These physical properties are respectfully useful for providingthe following functions as a plastic additive: impact modification,processing aid and melt strength enhancement, transparency or low haze.

[0203] In another embodiment of preparing a polymeric composition inwhich a polymeric component is modified by use of the multiple polymericadditive system, the polymer particles in the solid component may alsohave the following chemical properties: acrylic or saturated chemicalstructure; polymeric component with composition miscible or compatiblewith polymeric matrix. These chemical properties are respectfully usefulfor providing the following functions as plastic additives: thermal andUV stability, dispersion and ease of blending into the polymericcomponent.

[0204] In a specific embodiment of preparing the polymeric composition,the solid component of the multiple polymeric additive system is presentin an amount of more than 40 weight percent, said weight percentagebeing based on the total weight of the multiple polymeric additivesystem. If the solid component is present in an amount lower than 40weight percent, then the process for preparing the polymeric additivewill not be as economically efficient and eventual removal of the largeramount of liquid phase will be more technically difficult. Typically,the solid component is present in excess of 45 weight percent, moretypically in excess of 50 weight percent, and most typically in excessof 55 weight percent.

[0205] In another embodiment for preparing a polymeric composition, thesolid component of the multiple polymeric additive system is present inan amount of at most 99%, typically at most 75% weight percent, saidweight percentage being based on the total weight of the multiplepolymeric additive system. If the solid component is present in anamount greater than 75%, then agglomeration and/or high viscosity mayinterfere with handling and processing of the multiple polymericadditive system.

[0206] In another embodiment for preparing a polymeric composition, theliquid component of the multiple polymeric additive system may containessentially no water. Typically, however, the multiple polymericadditive system contains at least 5 weight percent water when it isadded to the process. During processing, however, any volatilecomponents, including water, may be devolatilized so that the remainingamount of liquid component in the polymeric composition after processingis reduced. The weight percentage of the multiple polymeric additivesystem remaining in the polymeric composition after processing can be inthe range of from less than 40% up to 100%, the weight percentage beingbased on the total weight of multiple polymeric additive system beingadded in the process. One embodiment in which less than 40% of themultiple polymeric additive system remains in the polymeric compositionafter processing occurs when all the liquid of a 50% solids multiplepolymeric additive system devolatilizes and a portion of the solidcomponent degrades, reacts, or changes form.

[0207] In one embodiment for preparing the polymeric composition, theweight fraction of the multiple polymeric additive system remaining inthe polymeric composition after processing can be in the range of from0.01% to 99%, the weight fraction being based on the total weight of themultiple polymeric additive system and the polymeric component.Typically, the weight fraction of the multiple polymeric additive systemremaining in the polymeric composition after processing ranges from 0.5to 40%, more typically from 0.5 to 25%, the weight fraction being basedon the total weight of the multiple polymeric additive system and thepolymeric component.

[0208] In one embodiment for preparing a polymeric composition, themultiple polymeric additive system's liquid component may be 100 weightpercent water. When the amount of water in the liquid component is lessthan 100%, then the liquid component may also contain at least oneliquid from the following group: organic solvents; alcohols; esters;plasticizers, such as dioctyl phthalate and the like; emulsionstabilizers; defoamers; leveling agents; biocides; UV stabilizers;lubricants; oils; dyes; rheology modifiers; thermal stabilizers;co-stabilizers; antiozodants; and mold release agents, oligomers,monomers, and the like.

[0209] In other embodiments of preparing a polymeric composition, themultiple polymeric additive system is in the form of at least one of thefollowing: an emulsion, suspension, dispersion, latex, paste, pellet,powder, or a wet-cake. Conditions for forming an emulsion, suspension,dispersion, latex, paste, pellet, powder, or a wet-cake are as follows:For emulsion, suspension, dispersion, latex, the basic conditions arethose that involve the formation or suspension of an existing polymerphase within a continuous liquid phase. The paste and wet-cake are thendistinguished by having partial removal of liquid phase and/or highconcentration of (typically agglomerated or coagulated) polymer phase.Pellets and powders would be distinguished by having virtually all thewater removed (99%) wherein smaller particles are agglomerated ormelt-fused into larger particles (e.g., larger than about 10 microns forpowders, macroscopic for pellets).

[0210] In one embodiment for preparing a polymeric composition, one ormore additional additives may be added along with the multiple polymericadditive system, or independent from the multiple polymeric additivesystem, to the process. These one or more additional additives include:waxes; pigments; opacifiers; fillers; exfoliated clays; toners;antistatic agents; metals; flame retardants; thermal stabilizers;co-stabilizers; antiozodants; cellulosic materials; impact modifiers;processing aids; lubricating processing aids; internal lubricants;external lubricants; oils; rheology modifiers; powder flow aids;melt-flow aids; dispersing aids; UV stabilizers; plasticizers; fillers;optical modifiers; surface roughness modifiers; surface chemistrymodifiers; adhesion modifiers; surface hardeners; compatibilizers;diffusion barrier modifiers; stiffeners; flexibilizers; mold releaseagents; processing modifiers; blowing agents; thermal insulators;thermal conductors; electronic insulators; electronic conductors;biodegradation agents; antistatic agents; internal release agents;coupling agents; flame retardants; smoke-suppressers; anti-drip agents;or colorants.

[0211] In an other embodiment of this process, one or more additionaladditives may be incorporated into the polymeric composition independentfrom the multiple polymeric additive system by one or more of thefollowing processes: adding the one or more additional additivesdirectly to the polymeric component during polymerization or manufactureof the polymeric component; post-blending the one or more additionaladditives into the polymeric component during powder blending orcompounding step; adding the one or more additional additives directlyinto the melt processing step; blending the one or more additionaladditives with yet an additional additive to form a blended additive,followed by adding the blended additive to the polymeric component or tothe polymeric composition.

[0212] In one embodiment for preparing a polymeric composition, thepolymeric component may contain at least one of any polymeric materialknown to those skilled in the art. Typical examples of polymericmaterials include those in the following group: aromatic polyesters,polycarbonate, styrene-acrylonitrile copolymers, styrenic resins, methylmethacrylate copolymers, polyolefins, polyvinyl halides,acrylonitrile-butadiene-styrene (“ABS”) resins, polyamides, epoxyresins, polyacetals, epoxy resins, polyurethanes, thermoset resins,polyketones, polyetheretherketones, as well as blends, grafts, andcopolymers thereof.

[0213] As types of polymers vary in their sensitivity to moisture andother contaminants present in water, certain multiple polymeric additivesystems will be preferred. Because PVC is not very sensitive to moistureunder typical processing conditions, then multiple polymeric additivesystems for PVC may contain water. However, certain polymers likearomatic polyesters must be essentially devoid of water duringprocessing. Other polymers such as polyamides absorb water and mayhydrolyze thereby forming various processing problems as well. Theselection of the liquid component of the multiple polymeric additivesystem will therefore vary with the intended polymeric component inwhich the multiple polymeric additive system will be used.

[0214] In one specific embodiment of the process of the presentinvention, a multiple polymeric additive system in the form of anemulsion containing more than 40 weight percent solid component and lessthan 60 weight percent water is added to a PVC powder masterbatch in ahigh speed mixer. In this example, the masterbatch typically containsvarious other additives such as lubricants, and stabilizers as known inthe art for preparing a rigid PVC profile. In this example, the multiplepolymeric additive system contains a population of acrylic processingaid polymeric additive particles and a population of acrylic impactmodifier polymeric additive particles. The mean particle diameter of thesmaller population is about 100 to 120 nm, and the mean particlediameter of the larger population is about 300 nm to 350 nm. The weightratio of the smaller to the larger polymer particle populations is about20:80. The impact modifier polymer particles are crosslinkedpolybutylacrylate core particles grafted with a polymethyl methacrylateshell. In the impact modifier, the polybutyl acrylate polymer is greaterthan 90%, the weight percentage based on the total core // shellparticle weight, so that the impact modifier polymer particles are notreadily isolatable as dry powders. The multiple polymeric additivesystem/PVC is blended in the high speed mixer thereby producing heat.Water is removed by vaporization arising from the heat generation. Afterthe water is removed, the weight fraction of the remaining solidcomponent of the multiple polymeric additive system in the polymericcomposition (i.e., the weight percent of the impact modifier particlesin the PVC masterbatch plus impact modifier) is between 1 and 20 weightpercent. The resulting polymeric composition is then extruded into aprofile. The resulting profile exhibits improved impact strength andprocesses smoothly compared to that of the unmodified PVC masterbatch.

[0215] In one embodiment for preparing a polymeric composition, one orboth steps of (I) contacting the polymeric component with a multiplepolymeric additive system to form a blend, and (II) removing at least apartial amount of the liquid component from the polymeric composition,may be performed with any type of equipment or operation known in theart or polymer and plastics processing. Examples of these processesinclude: standard melt processing techniques known to the industryincluding extrusion or co-extrusion, injection molding, thermoforming,calendering, blow molding, and the like.

[0216] In one embodiment for preparing a polymeric composition, whenforming the blend, the polymeric component reacts with at least aportion of the plastic additive system's liquid component. Reactivecomponents are useful for: enhancing the dispersion and adhesion betweenthe additive and the polymeric matrix. Examples include the following:incorporation of acid, amide, amines, epoxy groups, anhydridefunctionality; ionic functionality within the chemical structure of theadditive to promote reaction with selective groups in the polymer.Hydroxyl functionalities are also useful for providing compatibilitywith other polar components. Other examples include the addition of twopolymers one with an acid functionality and the other with an epoxidefunctionality so that they covalently bond during blend processing. Usesof such reactive additive components include improving sag resistance inpolymer components have low melt strength.

[0217] In one embodiment for preparing a polymeric composition, whenforming the blend, the polymeric component reacts with at least aportion of the plastic additive system's solid component. Specifically,the reactive solid components are useful in engineering resinapplications in which a reactive epoxide on the shell of a core-shellmatrix may react with for example a polyester. Also, use of acid in theshell can react with nylon. These reactions tend to modify the meltrheology and/or cause improved dispersion of the multiple polymericadditive system's solid component in the polymeric composition.

[0218] In one embodiment for preparing a polymeric composition, whenforming the blend, the polymeric component does not react with eitherthe plastic additive system's solid component or the plastic additive'sliquid component. Non-reactive components may be useful for forming of asecond phase to enhance the mechanical or rheological properties.Non-reactive components may also be useful for creating a miscible blendin which the polymeric component and one or more of the polymers in themultiple polymeric additive system are mutually dissolved in each other.Examples of non-reactive polymeric components include essentiallynon-functional polymers, i.e. polymers containing few or no functionalgroups, such as polyolefins and the like.

[0219] In one embodiment for preparing a polymeric composition, whenforming the blend, at least a portion of the plastic additive system'ssolid component reacts with at least a portion of the plastic additive'sliquid component. Reactive components are useful for incorporating andchemically bonding the plastic additive with the polymeric component inthe polymeric composition. Examples include the following: reactiveliquid rubbers suspended in styrene or other free-radically reactivemonomers as modifiers for thermoset systems, and the like.

[0220] In one embodiment for preparing a polymeric composition, whenforming the blend, the plastic additive system's solid component doesnot react with the plastic additive's liquid component. Non-reactivecomponents are useful for forming non-chemically bonded blend with finalsystem. Non-reactive components may also be used for enabling completeremoval of the liquid phase from the polymer composition. For example,adding a polymeric component suspended or dissolved in solvent or water,followed by drying or solvent evaporation is useful for removing theliquid phase from the polymer composition. Also, adding emulsified ornon-emulsified mineral oil to an aqueous-based polymeric emulsion as anadditive system can be useful for improving melt flow during subsequentprocessing steps. Also, the polymeric component may be dissolved ordispersed in a liquid lubricant or stabilizer.

[0221] In one embodiment for preparing a polymeric composition, whenforming the blend, at least a portion of the plastic additive system'ssolid component forms a by-product. By-product formation is useful wherethe by-product has a function in the polymeric composition. Typicalby-products which are useful may be formed during the blend process orformed during subsequent in-use aging of the product. Useful by-productsmay be formed during plastics processing conditions using any of anumber of known stabilizer technologies. For example, near at or above200° C., organotin mercaptides, calcium mixed metal carboxylates, andcertain organic-based stabilizers are known to react with the potentialformation of by-products to stabilize polymeric resins such as PVC.Typically the amounts of stabilizers is between 0.2% to 2% based onresin. During processing, these stabilizers undergo chemical change andthereby form by-products. The stabilizers may undergo complete orpartial chemical change to form by-products which are effective atreducing degradation in the PVC resin.

[0222] In one embodiment for preparing a polymeric composition, whenforming the blend, neither the plastic additive system's solid componentnor the plastic additive's liquid component forms a by-product.Typically, if the by-product is deleterious to the formed product, thenthe by-product particularly not useful. Examples of non-usefulby-product formation include the presence of: residual monomers in themultiple polymeric additive system which may lead to unacceptable odoror migration; water or other volatile components which may form gasesduring the melt processing step; catalysts or other reactive specieswhich may react and promote degradation or post-crosslinking of any ofthe polymers in the polymeric composition; residual salts or emulsifierswhich may promote thermal degradation. Examples include the following:sodium lauryl sulfate, commonly used as a surfactant, is typically knownin the art to form the by-products dilauryl ether and sodiumpyrosulfate. Such by-products can potentially cause color formation orother instability in the additive-matrix system. Also, ionic specieslike Ca++ can result in reactions or crosslinking with certain polymermatrices, while anionic species like Cl− can often result in corrosionof metals.

[0223] In one embodiment for preparing a polymeric composition, afterforming the blend, the blend may contain at least a portion of theplastic additive's liquid component. In this embodiment, the liquidcomponent may function as an additive, such as a plasticizer,stabilizer, lubricant, processing aid, and the like.

[0224] In a further embodiment for preparing a polymeric composition,after forming the blend, the blend may be formed into a productcomprising at least a portion of the plastic additive's liquidcomponent. This may occur when the polymer blend is melt processed andfabricated into a product using melt processing techniques that do notcompletely volatilize the liquid component. Typically, the liquidcomponent will have a boiling point near or above the melt processingtemperature, and/or the melt processing system is enclosed such that theescape of any volatile components is prevented. This is useful where theliquid component functions as an additive, such as plasticizer,lubricant, process aid, or stabilizer, and the like.

[0225] In the liquid removal step, the liquid may be removed form thepolymeric composition at various points in the processes, such asdewatering with the polymer matrix, dewatering prior to blending,dewatering during the blending, dewatering in the extruder and so forth.

[0226] In a further embodiment for preparing a polymeric composition,the blend may be formed into a product containing essentially none ofthe plastic additive's liquid component. This may occur when the liquidcomponent is removed during a drying, blending or melt processing step.Typically, the liquid is removed by drying or devolatilization by heatand removal of the gases formed. This process may also be assisted orachieved through other separation processes such as physical separation,e.g. filtering the liquid away from the solid. This is useful where thepresence of the liquid would be detrimental to the performance of thepolymeric composition. One specific example in which remaining liquidmay be detrimental is where the presence of water could adversely affectpowder properties of the polymeric composition. Remaining liquid mayalso be detrimental to the processing rheology of the polymer blend. Theappearance and integrity of final plastic parts may also be adverselyaffected by remaining liquid in the polymeric composition, such as incases where bubbles are formed due to the presence of water or othervolatiles during the melt processing step.

[0227] Thus, in a further embodiment for preparing a polymericcomposition, the blend may contain essentially none of the plasticadditive's liquid component. This can occur during the process where theliquid is removed either prior to or during the melt processing step.Further, in another embodiment the polymeric composition may contain atleast a second multiple polymeric additive system. One or moreadditional multiple polymeric additive systems are useful whereadditional additives are incorporated either directly into the polymercomponent or at some point in the subsequent blending, compounding,and/or melt processing steps. This is useful where additional functionsnot provided by the liquid additive are required or desired, such asthermal stabilization, lubrication, and the like.

[0228] Further, at least a portion of the second multiple polymericadditive system may react with at least a portion of the first multiplepolymeric additive system. Typical cases where the reactivity betweenadditives is being promoted, can occur when combining stabilizers withcertain co-stabilizers. Reactivity between additives is also importantwhere crosslinking and or grafting is desirable, such as in polyols andepoxides for curing certain resin systems.

[0229] Further, when forming the blend, at least a portion of the secondmultiple polymeric additive system reacts to form one or moreby-products. In this embodiment, by-product formation may occur inessentially the same fashion as any reactivity of the first polymericadditive as described above.

[0230] In further specific embodiment, when forming the blend,essentially none of the second multiple polymeric additive system mayreact to form a by-product. This is useful where, as described above forthe first multiple polymeric additive system, by-products are harmful,such as during the following situations: forming volatiles; formingcontaminants such as black specs on the surface of formed plasticarticles; forming contaminants which promote degradation, and the like.

[0231] In other specific embodiments for preparing a polymericcomposition, the polymeric composition further may contain at least oneof the following: waxes; pigments; opacifiers; fillers; exfoliatedclays; toners; antistatic agents; metals; flame retardants; thermalstabilizers; co-stabilizers; antiozodants; cellulosic materials; impactmodifiers; processing aids; lubricating processing aids; internallubricants; external lubricants; oils; rheology modifiers; powder flowaids; melt-flow aids; dispersing aids; UV stabilizers; plasticizers;fillers; optical modifiers; surface roughness modifiers; surfacechemistry modifiers; adhesion modifiers; surface hardeners;compatibilizers; diffusion barrier modifiers; stiffeners; flexibilizers;mold release agents; processing modifiers; blowing agents; thermalinsulators; thermal conductors; electronic insulators; electronicconductors; biodegradation agents; antistatic agents; internal releaseagents; coupling agents; flame retardants; smoke-suppressers; anti-dripagents; or colorants.

[0232] In another specific embodiment for preparing a polymericcomposition, the amount of the multiple polymeric additive system'sliquid component in the polymeric composition in the beginning of thecontacting step is in the range of from 0.01 weight percent to less than60 weight percent, said weight percentage being based on the totalweight of the polymeric composition at the beginning of the contactingstep. If the weight concentration is not within this range then theadvantages of this process are not achieved. More typically, this weightconcentration ranges from about 0.02 to 50%. Most typically this weightconcentration ranges from about 0.5 to 40%.

[0233] In one embodiment for preparing a polymeric composition, theamount of the multiple polymeric additive system's liquid componentremaining in the polymeric composition after step (II), wherein at leasta portion of the liquid component is removed, is in the range of frommore than 0% to 100 weight percent, said weight percent being based onthe total liquid component of the multiple polymeric additive systembefore a portion is removed. Typically, this weight percent is in therange of from about 0.02% to 99.5%, more typically from about 0.5% to50%, and most typically from about 0.5% to 25%, said weight percentbeing based on the total liquid component of the multiple polymericadditive system before a portion is removed.

[0234] In other specific embodiments for preparing a polymericcomposition, after forming the polymeric composition, the polymericcomposition may be directly formed into an article, used to form anarticle, or used further as an additive. In directly forming an articlefrom the polymeric composition, the polymeric composition is typicallysubjected to additional article forming processes without firstisolating the polymeric composition as set forth below. On the otherhand, when the polymeric composition is used to form an article, thenthe polymeric composition is typically first isolated into a form whichcan be readily used in polymer/plastics processing equipment for formingarticles. Examples of forms for ready use, include but are not limitedto: liquids, solutions, pastes, wet-cakes, dispersions, emulsions,lattices, powders, pellet, or tablet, and the like.

[0235] In another embodiment, the polymeric composition may be furtherused as an additive. In this case, the multiple polymeric additivesystem/polymeric component additive may be useful as an additiveconcentrate. Additive concentrates are typically provided in a solidform, such as a pellet, powder, or tablet, for subsequent processingwith polymers and plastics the same as or compatible with the polymericcomponent. The concentrated form of additives typically providesadditives which are easier to handle and disperse in polymericcomponents than that of the pure additive. Additive concentrates containat least 1 weight percent of the polymeric component to form themultiple polymeric additive system into said solid form. Typically,additive concentrates contain at least 5 weight percent, more typicallyat least 10 weight percent, and most typically at least 20 weightpercent of the polymeric component, said weight percentage being basedon the total weight of the polymeric composition.

[0236] Another embodiment of the present invention is forming an articlefrom the polymeric composition of the present invention. Article-formingprocesses include extrusion, calendering, injection molding,thermoforming, calendering, rotational molding, blow molding, and otherprocesses well know in the plastics processing art. All known plasticparts can be fabricated using these processes and polymericcompositions. Typical uses of the polymeric compositions of the presentinvention are found in all plastic and polymeric articles that can bemade using these processes. Typical examples of such articles include,but are not limited to: packaging materials such as plastic film andsheet; building and construction articles such as PVC siding andprofile; automobile and consumer durable articles such as polyolefinbody panels and engineering thermoplastic parts; electronics housingsand computer parts; thermoplastic elastomers used in sporting equipment;and the like.

1. A multiple polymeric additive system comprising: a) a liquidcomponent, and b) a solids component, the solids component comprisingpolymeric additive particles, the polymeric additive particlescomprising: (i) a first population of polymer particles, and (ii) asecond population of polymer particles, wherein the compositions of thefirst and second populations of polymer particles are different, andwherein the solids component is present in an amount of more than 40weight percent, said weight percent being based on the total weight ofthe multiple polymeric additive system.
 2. A multiple polymeric additivesystem as recited in claim 1 wherein the solid component is present inan amount of at least 45 weight percent, said weight percentage beingbased on the total weight of the multiple polymeric additive system. 3.A multiple polymeric additive system as recited in claim 1 wherein theliquid component comprises at least 5 weight percent water, said weightpercentage being based on the total weight of the multiple polymericadditive system's liquid component.
 4. A multiple polymeric additivesystem as recited in claim 1 wherein the liquid component comprisesessentially no water.
 5. A multiple polymeric additive system as recitedin claim 1 wherein the first population of polymeric additive particleshas a mean particle diameter in the range of from 10 nm to 50,000 nm. 6.A process for making a multiple polymeric additive system, the multiplepolymeric additive system comprising a liquid component and a solidscomponent, wherein the solids component comprises polymeric additiveparticles, said process comprising at least the following steps: (a)providing an aqueous emulsion polymerization reaction mixture comprisinga first population of polymer particles and a second population ofpolymer particles; and (b) polymerizing a first group of one or moreethylenically unsaturated monomers in the aqueous emulsionpolymerization reaction mixture, wherein after a portion of the firstgroup of one or more ethylenically unsaturated monomers is polymerized,the chemical compositions of the first and second populations of polymerparticles are different, wherein the solids component is present in anamount which is greater than 40 weight percent, wherein the weightpercentage is based on the total weight of the multiple polymericadditive system.
 7. A process for making a multiple polymeric additivesystem as recited in claim 6, wherein the weight ratio of the firstpopulation of polymer particles to the second population of polymerparticles are in the range of from 1:99 to 99:1.
 8. A process for makinga multiple polymeric additive system as recited in claim 6, furthercomprising the step of: (c) graft-polymerizing a second group of one ormore ethylenically unsaturated monomers in the presence of the first andsecond populations of polymer particles to provide a polymer adjacent tothe surfaces of the polymer particles of the first and secondpopulations, wherein the second group of one or more ethylenicallyunsaturated monomers are the same or different as the first group of oneor more ethylenically unsaturated monomers of step (b).
 9. A process formaking a multiple polymeric additive system as recited in claim 8,wherein the first group of monomers forms a rubbery core polymer and thesecond group of monomers forms a hard shell polymer.
 10. A process formaking a multiple polymeric additive system as recited in claim 9,wherein the rubbery core polymer is present in an amount of from 80 to99 weight percent, said weight percentage being based on the totalweight of the rubbery core and hard shell polymers.
 11. A polymericcomposition comprising a polymeric component and a polymeric additivecomponent, wherein said polymeric composition is prepared by a processwhich comprises at least the following steps: (I) forming a blendcomprising the polymeric component and at least one multiple polymericadditive system, wherein the multiple polymeric additive systemcomprises: a) a liquid component, and b) a solid component, the solidcomponent comprising polymeric additive particles, the polymericadditive particles comprising: (i) a first population of polymerparticles, and (ii) a second population of polymer particles, whereinthe compositions of the first and second populations of polymerparticles are different, and wherein the solids component is present inan amount of more than 40 weight percent, said weight percentage beingbased on the total weight of the multiple polymeric additive system. 12.A polymeric composition prepared by the process as recited in claim 11,wherein the solid component is present in an amount of at least 45weight percent, said weight percentage being based on the total weightof the multiple polymeric additive system.
 13. A polymeric compositionprepared by the process as recited in claim 11, wherein the liquidcomponent comprises at least 5 weight percent water, said weightpercentage being based on the total weight of the multiple polymericadditive system's liquid component.
 14. A polymeric composition asprepared by the process as recited in claim 11, wherein the meanparticle diameter of the first population of particles is at least 50%larger than the mean particle diameter of the second population ofparticles.
 15. A polymeric composition prepared by the process asrecited in claim 11, wherein the liquid component is present in anamount of at most 55 weight percent, said weight percentage being basedon the total weight of the multiple polymeric additive system.
 16. Aprocess for making a polymeric composition comprising a polymericcomponent and polymeric additive particles, said process comprising atleast the following steps: (I) contacting the polymeric component with amultiple polymeric additive system to form a blend, the multiplepolymeric additive system comprising: a) a liquid component, and b) asolid component, the solid component comprising polymeric additiveparticles, the polymeric additive particles comprising: (i) a firstpopulation of polymer particles, and (ii) a second population of polymerparticles, wherein the compositions of the first and second populationsof polymeric additive particles are different, and wherein the solidscomponent is present in an amount of more than 40 weight percent, saidweight percentage being based on the total weight of the multiplepolymeric additive system; and (II) removing at least a portion of theliquid component from the blend.
 17. A process for making a polymericcomposition as recited in claim 16, wherein step (I) the liquidcomponent is present in an amount of at most 55 weight percent, saidweight percentage being based on the total weight of the multiplepolymeric additive system.
 18. A process for making a polymericcomposition as recited in claim 16 wherein, after forming the blend, theblend is formed into an article.
 19. A process for making a polymericcomposition as recited in claim 16 wherein the polymeric component is inpowder form.
 20. A process for making a polymeric composition as recitedin claim 16 wherein the polymeric additive particles comprise at least10 percent by weight of a rubbery core.